The Immortal Cells

In 1951, researchers took tumor cells from an American patient named Henrietta Lacks. Against all expectations, these cells refused to die in the laboratory. They became the first "immortal" cell line in history and would be used in thousands of medical discoveries... without her family knowing for decades.

In most biology experiments, human cells survive only a few days in the laboratory, which, in the early 20th century, greatly constrained research: impossible to durably study a cancer, virus, or medication on stable cells. Everything changed in 1951, at Johns Hopkins Hospital in Baltimore, where Henrietta Lacks, a young African-American woman, was treated for a particularly aggressive cervical cancer. During examinations, doctors took tumor cells from her without her knowledge, according to a then-common practice rarely explained to patients.

Biologist George Gey immediately observed an unprecedented phenomenon: these cells did not die, they divided at a stupefying speed. For the first time, a human line seemed capable of surviving indefinitely in culture. Baptized "HeLa" after the first letters of Henrietta Lacks's name, it reached laboratories worldwide within years and became a central tool of modern biology.

HeLa cells contributed from the 1950s to the development of the polio vaccine, then served to study viruses, radiations, effects of microgravity, cancer mechanisms, or human chromosomes. But this scientific triumph covered a darker story: for decades, the Lacks family knew almost nothing of these cells' destiny, which companies massively produced and sold.

So robust they almost become an autonomous organism, they sometimes contaminate other cultures, to the point that several reputedly distinct lines proved invaded by HeLa. Their immortality is partly explained by abnormal activation of telomerase, the enzyme that prevents telomere shortening associated with cellular aging—a property that still fascinates researchers on cancer and longevity. The HeLa story fascinates because it mixes major discovery, bioethics, institutional racism, and research economics. Behind one of modern biology's most precious instruments stood a real person, whose name remained almost invisible for long.