HeLa cells are the first human cell line ever grown continuously in a laboratory, derived in 1951 from the cervical tumor of a thirty-one-year-old woman named Henrietta Lacks, and they have since become one of the most widely used biological tools in modern science. The cells have contributed to advances ranging from the polio vaccine to cancer drug screening to fundamental discoveries about how viruses enter human cells. But the story of HeLa is inseparable from a deeply troubling ethical history: the tissue was taken without Lacks’s knowledge or consent, her family received no compensation for decades, and the case has become a defining example of how biomedical research can exploit the people it claims to serve.
Who Was Henrietta Lacks
Henrietta Lacks was a Black tobacco farmer from southern Virginia who sought treatment for cervical cancer at Johns Hopkins Hospital in Baltimore, the only hospital in the area that would treat Black patients. She was treated in a segregated “colored ward.” During her care, a portion of her cervical biopsy was passed, without her knowledge, to George Gey, the head of tissue culture research at Hopkins.1Journal of the History of Medicine and Allied Sciences. The Immortal Life of Henrietta Lacks Gey had been trying for years to grow human cells that would survive outside the body long enough to be useful for research. Previous attempts always failed; the cells would divide a handful of times and die. Lacks’s tumor cells did something different. They kept dividing, doubling their population roughly every 24 hours. Gey quickly recognized their potential and began distributing them to other researchers. Lacks herself died of her cancer in October 1951, leaving behind a husband and five children. She never knew her cells had been taken, and her family would not learn of their existence for more than two decades.
Why HeLa Cells Never Stop Growing
Normal human cells have a built-in limit on how many times they can divide before they stop and die, a boundary set in part by structures called telomeres at the ends of chromosomes. Each time a cell divides, its telomeres get a little shorter, until eventually the cell can no longer replicate. HeLa cells sidestep this limit. They produce telomerase, an enzyme that rebuilds telomeres after each division, effectively preventing the countdown from reaching zero.2PubMed. Telomerase activity in HeLa cervical carcinoma cell line proliferation Researchers tracking HeLa cultures have found that mean telomere length stays stable over at least 60 population doublings, meaning the cells show no signs of aging even after months of continuous growth.3PubMed. Telomere length dynamics in telomerase-positive immortal human cell populations
The other key factor behind HeLa’s aggressive growth is the virus that caused Lacks’s cancer in the first place. Human papillomavirus type 18 (HPV-18) integrated its DNA into a specific location on chromosome 8 in Lacks’s cells, where it hijacked the activity of a nearby gene called c-Myc, a well-known driver of cell proliferation. Research has shown that the integrated viral DNA produces a hybrid RNA molecule that promotes tumor growth through a specialized molecular process.4PubMed. Chimera RNA transcribed from integrated HPV18 genome with adjacent host genomic region promotes oncogenic gene expression through condensate formation Whole-genome sequencing of HeLa has confirmed strong activation of the MYC gene by HPV-18 from a position roughly 500 kilobases upstream on the same chromosome.5PubMed Central. The haplotype-resolved genome and epigenome of the aneuploid HeLa cancer cell line Together, these two properties, telomerase keeping the clock from running out and a viral oncogene keeping the growth signal stuck in the “on” position, explain why HeLa cells are considered “immortal.”
A Genome Unlike Any Normal Human Cell
HeLa cells are not just abnormal in their growth behavior. Their entire genome has been profoundly rearranged compared to typical human cells. Normal human cells carry 46 chromosomes. HeLa cells are roughly triploid, meaning they carry something closer to three copies of many chromosomes rather than the usual two. Different HeLa strains show chromosome counts ranging from the mid-50s to the high 70s, and in some subclones, individual cells carry well over 100 chromosomes.6Scientific Reports. High variability of genomic instability and gene expression profiling in different HeLa clones This wide scatter is not a fluke of mixed cell populations; even cultures grown from a single founding cell produce daughter cells with wildly different chromosome numbers, suggesting that the genome is fundamentally unstable and generating new rearrangements with every round of division.
This genomic chaos matters for researchers who use HeLa. Whole-genome sequencing has mapped HeLa’s extensive copy-number variations and regions where one parental copy of a gene has been lost entirely, revealing a landscape far more scrambled than even most cancer genomes.5PubMed Central. The haplotype-resolved genome and epigenome of the aneuploid HeLa cancer cell line Different HeLa strains maintained in different laboratories have diverged from one another over years of independent culture, accumulating distinct mutations and structural changes. A HeLa culture in one lab may not behave identically to a HeLa culture in another, which can make it harder to compare results across studies that nominally use the same cell line. Researchers increasingly treat “HeLa” not as one thing but as a family of related but genetically distinct sub-lines.
Scientific Contributions Across Decades
The impact of HeLa on biomedical research is difficult to overstate. The cell line has appeared in an estimated 75,000 research studies and has been the subject of more than 17,000 patents, forming the foundation of what has become a multi-billion-dollar market in biological materials and related technologies.7Journal of Intellectual Property Law & Practice. Patenting human biological materials and data: balancing the reward of innovation with the ordre public and morality exception
One of the earliest and most consequential uses came in the 1950s, when massive quantities of HeLa cells were needed to test Jonas Salk’s polio vaccine. Tuskegee University played a central role in mass-producing HeLa cells and distributing them for the polio effort, a historical contribution that is less widely remembered than it deserves.8PubMed Central. Development of the polio vaccine: a historical perspective of Tuskegee University’s role in mass production and distribution of HeLa cells The cells also became a standard platform for cancer drug development. Researchers have used HeLa and drug-resistant variants derived from it to test dozens of chemotherapy agents, including widely used drugs like paclitaxel, cisplatin, and doxorubicin.9Biological and Pharmaceutical Bulletin. Cytotoxic Effects of 27 Anticancer Drugs in HeLa and MDR1-Overexpressing Derivative Cell Lines HeLa remains a common reference cell line for screening potential anticancer compounds, including experimental extracts from plants and natural products.10KnE Life Sciences. CYTOTOXICITY AND APOPTOSIS INDUCTION BY KAFFIR LIME LEAVES EXTRACT (Citrus hystrix DC.) IN HeLa CELLS CULTURE (HUMAN CERVICAL CANCER CELL LINE)
HeLa has been equally central to virology. Because the cells are easy to infect with many different viruses, they serve as a workhorse for studying how viruses get inside cells and what happens once they do. Studies using HeLa have revealed that herpes simplex virus can enter cells through a pH-dependent pathway involving endocytosis, a mechanism distinct from how the same virus enters other cell types.11PubMed Central. Roles for endocytosis and low pH in herpes simplex virus entry into HeLa and Chinese hamster ovary cells Other work has shown that vaccinia virus uses an unusual route to penetrate HeLa cells, relying on a previously unknown protein and a form of fluid-phase endocytosis that does not require the standard cellular machinery most viruses depend on.12PubMed Central. A novel cellular protein, VPEF, facilitates vaccinia virus penetration into HeLa cells through fluid phase endocytosis Even relatively obscure viruses like Oropouche virus have been studied in HeLa, where researchers found it enters through a different mechanism involving clathrin-coated vesicles and acidification of internal compartments.13PubMed Central. Oropouche virus entry into HeLa cells involves clathrin and requires endosomal acidification These findings, each revealing that different viruses exploit different doorways into the same cell, have been important for understanding viral biology broadly and for guiding antiviral drug development.
The Contamination Problem
HeLa’s vigor, the same relentless growth that makes it so useful, created a problem that haunted cell biology for decades. HeLa cells are so hardy and fast-growing that they can take over other cultures. If even a tiny number of HeLa cells are accidentally introduced into a flask of, say, liver cells or bladder cancer cells, the HeLa cells will eventually outcompete and replace the original culture entirely. The researcher may not realize anything has happened; the cells look like cells. But experiments done on those cultures are actually studying HeLa, not what the label on the flask says.
HeLa is the single most frequent source of cross-contamination among human cell lines.14PubMed Central. Discovery of HeLa Cell Contamination in HES Cells: Call for Cell Line Authentication in Reproductive Biology Research Well-known cell lines including WISH, KB, Hep-2, Chang Liver, INT407, and several others have been demonstrated to be HeLa in disguise.15Scientific Reports. A Combination of Species Identification and STR Profiling Identifies Cross-contaminated Cells from 482 Human Tumor Cell Lines One striking example is the bladder cancer cell line KU7, which was used in urological research for years before genetic profiling revealed it was actually HeLa.16PubMed Central. Hiding in plain view: genetic profiling reveals decades old cross contamination of bladder cancer cell line KU7 with HeLa Every paper published using KU7 that was actually studying HeLa cervical cancer cells rather than bladder cancer cells contributed potentially misleading findings to the literature. Multiply that across dozens of contaminated lines and you get a sense of the scale of the problem.
The solution, now increasingly mandated by journals and funding agencies, is routine authentication of cell lines using a DNA-based technique called short tandem repeat (STR) profiling. This method produces a simple numerical code that serves as a fingerprint for each cell line, is reproducible across laboratories, and is inexpensive enough for routine use.17PubMed. Short tandem repeat profiling provides an international reference standard for human cell lines Efforts to build publicly searchable STR databases are ongoing, so that any researcher can check their culture’s identity against a reference standard before publishing results.18PubMed Central. Short tandem repeat profiling: part of an overall strategy for reducing the frequency of cell misidentification The HeLa contamination saga is a cautionary tale about how quickly convenience and assumptions can undermine years of research.
Consent, Race, and Exploitation
The ethical dimensions of HeLa begin with a straightforward fact: Henrietta Lacks never agreed to have her cells used for research, and neither did anyone in her family. In 1951, there was no legal requirement for informed consent to take tissue during surgery or biopsy. Doctors routinely kept surgical specimens for research without telling patients. But the absence of a legal requirement does not mean what happened was ethically defensible, and Lacks’s case is made more troubling by the context in which it occurred. She was a Black woman being treated in a segregated hospital in the Jim Crow era, with no meaningful ability to question or refuse what was being done with her body.1Journal of the History of Medicine and Allied Sciences. The Immortal Life of Henrietta Lacks
Her story has become a prominent example of institutional racism in the American healthcare system during the mid-twentieth century, illustrating how Black patients were disproportionately subjected to medical exploitation without knowledge or consent.19PubMed Central. Henrietta Lacks and America’s dark history of research involving African Americans The commercialization of her biological materials adds another layer. HeLa cells have generated enormous revenue for biotech companies, cell banks, and research institutions. Lacks’s family, many of whom struggled with poverty and lacked health insurance for much of their lives, received none of that money for decades. The disconnect between the immense scientific and commercial value extracted from her cells and the zero compensation returned to her descendants has become one of the most widely discussed examples of inequity in biomedical research.
The lack of consent did not impede the patentability of inventions based on HeLa, a point that legal scholars have noted as evidence that intellectual property law has historically treated the cell donor as irrelevant in the chain of value creation.7Journal of Intellectual Property Law & Practice. Patenting human biological materials and data: balancing the reward of innovation with the ordre public and morality exception In 2021, seventy years after Lacks’s death, the World Health Organization held a ceremony to honor her unknowing contribution to medicine and science.
Genomic Privacy and the 2013 Controversy
The ethical questions around HeLa took on a new dimension in 2013, when a European research group published the full genomic sequence of a HeLa strain. The genome was made freely available online. Scientists quickly pointed out that because genomic data reveals heritable information, anyone with access to the HeLa sequence could infer genetic predispositions not just of Henrietta Lacks but of her living descendants, who had not been consulted. The backlash was swift. The data was pulled from public databases, and the National Institutes of Health negotiated an agreement with the Lacks family that established a system of controlled access for HeLa genomic data. Researchers who want to use the sequence must now apply to a committee that includes members of the Lacks family.
This episode forced the scientific community to confront a question it had mostly avoided: when you sequence a cell line derived from a real person, whose privacy rights apply? The Lacks case helped catalyze broader regulatory proposals in the United States around informed consent for biospecimens, extending beyond HeLa to the millions of tissue samples stored in biobanks nationwide.20PubMed Central. Lessons from HeLa Cells: The Ethics and Policy of Biospecimens The conversation is ongoing and unresolved. The practical challenge is real: many of the most scientifically valuable samples in biobanks were collected decades ago under consent practices that would be inadequate by today’s standards, and retroactively obtaining consent from donors or their descendants is often impossible.
Public Awareness and the Biobank Debate
Much of the public visibility around HeLa ethics owes its momentum to Rebecca Skloot’s 2010 book, The Immortal Life of Henrietta Lacks, which brought Lacks’s story to a mass audience for the first time. The book’s influence on media and policy has been measurable. Analysis of media coverage following the book’s publication found that informed consent dominated public discussion, appearing as a major focus in about 39 percent of media articles and transcripts and as a minor focus in roughly 45 percent. Other prominent themes included the welfare of vulnerable populations and the question of donor compensation.21PubMed Central. Bioethics in popular science: evaluating the media impact of The Immortal Life of Henrietta Lacks on the biobank debate
The media attention reshaped the conversation in ways that academic bioethics alone had not managed. Before Skloot’s book, the debate about consent for stored tissue samples was largely confined to specialist journals and policy meetings. Afterward, it became a cultural touchpoint, invoked in discussions about patient rights, racial justice, and the obligations of research institutions. The story gave a name and a face to what had previously been an abstract policy question, and that shift in framing has proved durable.
How HeLa Changed the Rules for Future Research
The Lacks case did not just generate outrage; it changed practice. The HeLa story has been explicitly cited as a catalyst for major regulatory proposals around the use of human biospecimens in the United States.20PubMed Central. Lessons from HeLa Cells: The Ethics and Policy of Biospecimens Institutional review boards now generally require explicit informed consent for the use of identifiable tissue in research, and many biobanks have moved toward broad-consent models that explain, at the time of collection, the types of future research the samples might be used for. These are not perfect solutions. Broad consent can be so vague that donors do not fully understand what they are agreeing to, and the question of whether descendants should have ongoing rights over a deceased relative’s biological material remains legally and philosophically unsettled.
On the compensation front, the Lacks family pursued legal action against companies that had profited from HeLa cells. In 2023, a settlement was reached with a major biotechnology firm, though the terms were not publicly disclosed. The settlement was widely discussed as a landmark moment, but it was the resolution of one family’s claim against one company, not a systemic fix. There is no general legal framework in the United States that entitles tissue donors or their families to a share of profits derived from their biological materials. The prevailing legal doctrine, established in a 1990 California Supreme Court case involving a different patient, holds that individuals do not retain property rights over cells once those cells have been removed from their body. Whether that doctrine will survive in an era of personalized genomics and lucrative cell-based therapies is an open question.
HeLa Cells and the Limits of Any Single Cell Line
For all its contributions, HeLa has a limitation that researchers increasingly acknowledge: it is one cell line from one patient with one type of cancer, and its extreme genomic instability means it may not always be a reliable stand-in for normal human biology. The very features that make HeLa immortal, its activated oncogenes and scrambled chromosomes, also make it behave differently from typical human cells in ways that can skew experimental results. Drug sensitivity measured in HeLa may not translate cleanly to other cell types or to tumors in living patients. Research on certain metabolic assays has shown that some anticancer drugs cause changes in HeLa mitochondria that can confound standard tests used to measure whether cells are alive or dead, potentially leading to inaccurate assessments of drug effectiveness.22PubMed Central. Anti-cancer drug-mediated increase in mitochondrial mass limits the application of metabolic viability-based MTT assay in cytotoxicity screening
None of this means HeLa is useless or outdated. It remains an indispensable tool for certain kinds of research, particularly in virology and basic cell biology where having an easily cultured, well-characterized human cell line is more important than having a perfect model of normal tissue. But the field has moved toward using panels of multiple cell lines, patient-derived cultures, and organoids when the goal is to model how drugs or diseases behave in diverse human populations. HeLa opened the door to cell-based research. The challenge now is making sure science does not lean too heavily on any single line, particularly one with such an unusual genome and such a fraught history.
George Gey and the Roller Drum
George Gey deserves a complicated place in this story. He was a genuine innovator in tissue culture technology, credited with developing the roller drum apparatus that kept cells bathed in nutrients and allowed them to grow more reliably than in static dishes.23PubMed. The Tissue Culture Laboratory of Dr. George Otto Gey 60 yrs ago as recalled by a former student He introduced new culture media using human fetal cord serum and beef embryo extract, advancing a field that had struggled for decades with the basic problem of keeping human cells alive outside the body. When he succeeded with HeLa, he freely distributed the cells to other researchers without seeking personal profit. Gey himself died of pancreatic cancer in 1970, and by some accounts, he asked that his own cells be cultured after his death, though the attempt reportedly failed.
Gey’s willingness to share HeLa widely is part of why the cells spread so rapidly through the global research community, enabling the polio vaccine work and much else. But that same open distribution, without any system for tracking or consent, is also what made the contamination crisis possible and what allowed a multi-billion-dollar industry to grow on a foundation of tissue taken from a woman who never knew it existed. Whether Gey is remembered primarily as a scientific pioneer or as someone who participated in exploitation depends on how much weight you give to the ethical standards of his era versus those of ours. Both readings are defensible, and neither is complete without the other.