HeLa, the first immortal human cell line on record to be successfully isolated and proliferated by a laboratory, was taken from Henrietta Lacks in 1951 at Johns Hopkins Hospital in Baltimore, Maryland.

[citation needed] Immortalised cell lines can also be cloned, giving rise to a clonal population that can, in turn, be propagated indefinitely.

The alternative, performing an analysis on primary cells from multiple tissue donors, does not have this advantage.

The cells are used for a wide variety of purposes, from testing toxicity of compounds or drugs to production of eukaryotic proteins.

[citation needed] While immortalised cell lines often originate from a well-known tissue type, they have undergone significant mutations to become immortal.