In biological and medical research, a HeLa cell is a cell which is derived from cervical cancer cells taken from a woman named Henrietta Lacks, who died from the cancer in 1951, and circulated (without Lacks's knowledge or permission) by George Gey . These cancer cells are considered "immortal" (that is, they do not die of old age and can divide an unlimited number of times, unlike most other human cells), and have been grown in cell culture in an unbroken lineage ever since.
This cell line was propagated for use in cancer research. Initially, the cell line was said to be named after a "Helen Lane", in order to preserve Lacks's anonymity. The cells proliferate abnormally rapidly, even compared to other cancers.
HeLa cells have been transformed by human papillomavirus 18 (HPV18), and have different properties from normal cervical cells.
They are used as model cancer cells and for studying cellular signal transduction.
HeLa cells have proven difficult to control. They sometimes contaminate other cell cultures growing in the same laboratory, interfering with biological research. The degree of contamination is unknown, because few researchers test the identity or purity of already-established cell lines. It has been claimed that a substantial fraction of in vitro cell lines are actually HeLa, their original cells having been overwhelmed by a rapidly growing population derived from HeLa contaminant cells. It has been estimated that the total mass of HeLa cells far exceeds that of the rest of Henrietta Lacks' body.
Some researchers have argued that these cells are a separate species, because they reproduce and spread on their own; in 1991 it was named and described as Helacyton gartleri.