HeLa cells is the oldest immortalized cell line and widely used in research, derived from cancer cells taken from Henrietta Lacks in February 1951. In this scanning electron micrograph, colorized HeLa cells are undergoing apoptosis or programmed cell death. The string-like microvilli are used by the cells to move around and metastasize.
Image courtesy of Thomas Deerinck, UC San Diego, NIGMS and NIH.