Topic summary
Cell line

Extracted from the Wikipedia article Immortalised cell line.
Relation to natural biology and pathology
There are various immortal cell lines. Some of them are normal cell lines (e.g. derived from stem cells). Other immortalised cell lines are the in vitro equivalent of cancerous cells. Cancer occurs when a somatic cell that normally cannot divide undergoes mutations that cause deregulation of the normal cell cycle controls, leading to uncontrolled proliferation. Immortalised cell lines have undergone similar mutations, allowing a cell type that would normally not be able to divide to be proliferated in vitro. The origins of some immortal cell lines – for example, HeLa human cells – are from naturally occurring cancers. 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.