Henrietta Lacks was born Loretta Pleasant on August 1, 1920, in Roanoke, Virginia, the daughter of Eliza and Johnny Pleasant. On her father's side, she was descended from slaves who were imprisoned on a tobacco plantation, while on her mother's side she came from a white slave owner and a former slave who remained on a tobacco plantation to work as a sharecropper following emancipation.

When she was four, her mother died giving birth to her 10th child. Her father, unable to look after them all, moved the family to Clover, Virginia, and the children went to live with relatives. Loretta, now nicknamed Henrietta (no one really knows why) went to live with her grandfather, Tommy Lacks, in what used to be the slave quarters of the plantation owned by her great-grandfather and her great-uncle, sharing a room with her cousin David "Day" Lacks, who would later become her husband.

Lacks moved to Halifax County, Maryland, with her husband and two children, where she had three more children. When her last child was born, she was diagnosed with cervical cancer. 

October 4, 1951, aged just 31, she died. But her cells didn't.

After Lacks showed up at Johns Hopkins hospital – the only one in the area that would treat black patients – complaining of a "knot" inside her, doctors diagnosed her with cancer and began treating her with radium implants, a crude treatment that was standard at the time. As part of her treatment, tissue samples were collected without her consent. Upon analysis, doctors found that her cells continued to reproduce long after cells from virtually all other samples would die off outside their host, and at a very high rate. The cells became known as the "HeLa immortal cell line".

It's difficult to undersell the importance of these cells to research. Most cells cultured for lab research die within a few days, making it impossible to perform a variety of tests on the sample. Now, with an "immortal" cell that could divide and replicate, researchers could undertake all kinds of research, from cloning to in vitro fertilization, that they couldn't undertake before. 

In 1954, Jonas Salk used Lacks' cells in his research developing the polio vaccine, mass-producing the cells in order to test his team's product. After this, her cells were in high demand and were produced for commercial and medical research for scientists around the world. Over 50 million tons of her cells have been produced and used in over 60,000 scientific studies. All without her consent, and for many years without her family's knowledge.

"Twenty-five years after Henrietta died, a scientist discovered that many cell cultures thought to be from other tissue types, including breast and prostate cells, were in fact HeLa cells," journalist Rebecca Skloot told Smithsonian Magazine in a 2010 interview about her book The Immortal Life of Henrietta Lacks.

Scientists had realized that HeLa cells could travel through the air on dust particles, get themselves on unwashed hands, and contaminate other cultures in the same lab. This was a huge problem, but one team of researchers thought they had a solution: They would track down Henrietta's family and use their DNA to map her genes, which would allow them to tell which cell cultures were her cells and which were not. Another problem arose; when they did track her family down they were completely unaware that her cells had been used. Her husband, who had a third-grade education, wasn't scientifically literate. Communicating the situation to him did not go well.

"The way he understood the phone call was: 'We’ve got your wife. She’s alive in a laboratory. We’ve been doing research on her for the last 25 years. And now we have to test your kids to see if they have cancer,'" Skloot told Smithsonian Magazine.

For Henrietta's daughter, Deborah, who was young when her mother died, the news was even more confusing. She had questions, Skloot said, such as did it hurt when her mother's cells were injected with viruses and had they cloned her.

Then there was, of course, the compensation aspect. The family, who had lived in poverty for years and included one homeless member, discovered Lacks' cells had been used to create a multi-billion dollar industry.

They were, understandably, livid. Unfortunately, as far as the law was concerned, they didn't have a case. In 1976, another cancer patient, John Moore, was found to have cells valuable to medical research. His blood cells produced a protein that could stimulate the growth of white blood cells. His doctor didn't tell him this. Instead, when he asked his doctor if he could visit a closer practitioner to make it more convenient to give medical samples, the doctor offered to pay his flight and accommodation expenses.

Moore finally twigged something was amiss when he was asked to sign the declaration "I (do, do not) voluntarily grant to the University of California all rights I, or my heirs, may have in any cell line or any other potential product which might be developed from the blood and/or bone marrow obtained from me".

The doctor and his research assistant profited from Moore's cell line, for which Moore sued. The Supreme Court of California, however, eventually ruled that a person doesn't have a right over their cells, even if they prove profitable to scientists.

Chances of getting money for Lacks' cell line were very small. However, in 2013, researchers published the DNA of HeLa cells, to the shock of her family, who were only informed by Rebecca Skloot. They were concerned about genetic information about Lacks being publically available, and what could be gleaned about her children and grandchildren. This time, an agreement was reached that gave the family some control over how the sequence data was used and credited the family in scientific papers on the sequencing.

Henrietta Lacks, though she didn't know it, has saved countless lives and contributed to many breakthroughs around the world. Finally, decades after her death, some reparations are being made. A major biomedical-research organization, the Howard Hughes Medical Institute (HHMI), donated a six-figure sum to the Henrietta Lacks Foundation in October this year. 

“We felt it was right to acknowledge Henrietta for the use of HeLa cells and to acknowledge that the cells were gained inappropriately,” Erin O’Shea, president of the HHMI told Nature. “And to acknowledge that we have a long way to go before science and medicine are really equitable.” 

Founded by Skloot, the foundation gives grants to people who have been part of medical research studies without their knowledge, and the families who received nothing for that work.