The oldest, living, cultured human cells are the HeLa cell line. All HeLa cells are derived from Henrietta Lacks (1920–1951), a 31-year-old woman from Baltimore, Maryland, who died of cervical cancer in 1951. Epithelial tissue obtained by biopsy became the first continuously cultured human malignant cells. From this culture, scientists were able to discover that 80 to 90 percent of cervical carcinomas contain human papillomavirus DNA. HeLa cells are used in many biomedical experiments.