Henrietta Lacks died from cervical cancer in 1951, but over the past half century she has made an unparalleled contribution to medical science.

This is because while Henrietta is long dead, her cells live on.

When she was admitted to Johns Hopkins Hospital in Baltimore, US, the doctor George Gey found that while regular human cells only divide around 50 times before they die, those in Henrietta's tumour went on dividing indefinitely.

No one knows why.

Without Lacks' consent, cells were taken from her tumor for use in research.

Her immortal cells have gone on to help develop a polio vaccine and have been pivotal in research into Aids/HIV and the effects of radiation.

Source: Al Jazeera