Henrietta Lacks was a poor Southern tobacco farmer who worked the same land as her slave ancestors and was buried in an unmarked grave when she died, yet her cells—taken without her or family’s knowledge—became the first “immortal” human cells grown in culture. The story of the Lacks family—past and present—is inextricably connected to the dark history of experimentation on African Americans, the birth of bioethics, and the legal battles over whether we control the stuff we are made of.