HeLa cells are the first human cells ever grown successfully in a laboratory, and they’ve been dividing endlessly since 1951. Taken from a cervical cancer tumor belonging to a woman named Henrietta Lacks, these cells became the foundation for some of the most important medical advances of the past century, from polio vaccines to cancer research to COVID-19 studies. They also raised profound questions about consent, race, and who profits from the human body.
Where HeLa Cells Came From
On February 1, 1951, a 30-year-old African American tobacco farmer named Henrietta Lacks visited Johns Hopkins Hospital in Baltimore with a painful lump in her cervix and bloody vaginal discharge. Doctors diagnosed her with cervical cancer. Before treating her, a surgeon removed cells from her tumor for research purposes, without her knowledge or permission. This was standard medical practice at the time.
Eight days later, during a follow-up visit, Dr. George Otto Gey obtained another sample of the tumor. He brought those cells back to his lab and placed them in a culture dish, just as he had done with tissue samples from many other patients. But something unprecedented happened: these cells didn’t die after a few divisions the way every other human cell sample had. They kept growing. They doubled roughly every 24 hours and showed no signs of slowing down. Gey named them “HeLa,” using the first two letters of Henrietta’s first and last name.
Henrietta Lacks died on October 4, 1951, at age 31. Her cells, however, have never stopped dividing.
Why HeLa Cells Won’t Die
Normal human cells have a built-in expiration date. Every time a cell divides, the protective caps on the ends of its chromosomes (called telomeres) get a little shorter. After roughly 50 divisions, the caps wear down enough that the cell stops dividing and dies. This is a natural part of aging at the cellular level.
HeLa cells bypass this limit because they produce unusually high amounts of an enzyme called telomerase, which rebuilds those protective caps after every division. The caps never shorten, so the cells never receive the signal to stop. This trait came from the aggressive cancer that killed Henrietta Lacks: the same mutation that made the tumor so deadly also made the cells essentially immortal in a lab dish. Research on this very mechanism in HeLa cells contributed to a 2009 Nobel Prize, awarded to three scientists who showed how telomeres and telomerase control cell aging and breakdown.
Major Medical Breakthroughs
By 1952, HeLa cells were being shipped to laboratories around the world. Their first major impact came almost immediately. Scientists needed a reliable way to test whether Jonas Salk’s new polio vaccine actually worked, and that required growing the poliovirus in human cells. HeLa cells could be produced in enormous quantities cheaply and quickly, making mass testing possible. The polio vaccine was declared safe and effective in 1955, and HeLa cells played a direct role in getting it there.
From that point on, HeLa cells became the default tool for an extraordinary range of research. Scientists used them to study how viruses infect human cells, how cancer develops and spreads, and how cells respond to radiation and toxic substances. The 1989 discovery that telomerase rebuilds chromosomal caps was made using HeLa cells, opening up an entirely new field of aging research. They’ve also been used in studies on gene mapping, cell signaling, and the effects of pharmaceutical compounds, contributing to at least five Nobel Prize-winning lines of research.
More recently, researchers engineered HeLa cells to express the ACE2 receptor (the protein that the COVID-19 virus uses to enter human cells) and used them to study how the virus infects cells, test antibody responses from recovered patients, and evaluate potential treatments. These modified HeLa cells proved more sensitive at detecting replicating virus than some of the other cell lines commonly used in COVID research.
A Billion-Dollar Industry Without Consent
Henrietta Lacks never agreed to have her cells used for research. Her family didn’t learn about HeLa cells until more than 20 years after her death, when researchers contacted them to take blood samples for further study. Meanwhile, HeLa cells had become a commercial product. Today, a single vial of engineered HeLa cells sells for around $3,000 from major suppliers like Thermo Fisher Scientific. The cells have been bought and sold by laboratories, pharmaceutical companies, and biotech firms for decades.
The Lacks family saw none of this money. For years, Henrietta’s descendants lived without health insurance while her cells generated enormous profits for others. The ethical questions this raised helped reshape how the medical community thinks about informed consent and the use of human biological materials in research.
In 2013, when researchers published the full HeLa genome sequence without consulting the family, it sparked a new controversy. The genome could potentially reveal genetic information about Henrietta’s living descendants. The NIH worked with the Lacks family to create a formal agreement: researchers who want access to HeLa genomic data must now apply through a controlled database, and two members of the Lacks family sit on the committee that reviews those requests. The agreement was designed to balance open science with the family’s privacy.
In 2023, the Lacks estate reached an undisclosed settlement with Thermo Fisher Scientific. The family’s lawyers argued that the company had continued to profit from HeLa cells long after the ethical problems with their origin became widely known.
The Contamination Problem
The same aggressive growth that makes HeLa cells so useful in the lab also created a serious scientific problem. HeLa cells are so hardy and fast-growing that they can take over other cell cultures. By the early 1970s, evidence began mounting that HeLa cells had contaminated cell lines in laboratories worldwide. Cultures that researchers believed were breast cancer cells, or even mouse cells, turned out to be HeLa cells that had somehow gotten into the samples and outcompeted the original cells.
The implications were significant: years of published research on supposedly distinct cell types may have actually been conducted on HeLa cells, casting doubt on the findings. The debate over this contamination problem was contentious when it first emerged and, according to researchers, has never been fully resolved. It remains a known risk in cell biology labs today, requiring careful authentication of cell lines before they’re used in experiments.
Why They Still Matter
More than 70 years after Henrietta Lacks’ death, HeLa cells remain one of the most widely used tools in biomedical research. They’ve contributed to over 110,000 published scientific papers. They’re affordable enough that nearly any research lab can work with them, they grow reliably, and their biology is more thoroughly documented than perhaps any other human cell line in existence. When a new virus emerges, when a drug needs initial testing, when scientists want to understand a basic question about how human cells work, HeLa cells are often the first place they turn.
They also stand as a reminder that scientific progress doesn’t happen in a vacuum. The story of Henrietta Lacks forced a reckoning with the way research institutions treated Black patients, the gaps in informed consent, and the question of who benefits when one person’s biology becomes the foundation for an entire industry. Her cells changed medicine. Her story changed how we think about the ethics of that medicine.