It's The Immortal Life of Henrietta Lacks. This is from Amazon:
From a single, abbreviated life grew a seemingly immortal line of cells that made some of the most crucial innovations in modern science possible. And from that same life, and those cells, Rebecca Skloot has fashioned in The Immortal Life of Henrietta Lacks a fascinating and moving story of medicine and family, of how life is sustained in laboratories and in memory.
Henrietta Lacks was a mother of five in Baltimore, a poor African American migrant from the tobacco farms of Virginia, who died from a cruelly aggressive cancer at the age of 30 in 1951. A sample of her cancerous tissue, taken without her knowledge or consent, as was the custom then, turned out to provide one of the holy grails of mid-century biology: human cells that could survive--even thrive--in the lab.
Known as HeLa cells, their stunning potency gave scientists a building block for countless breakthroughs, beginning with the cure for polio. Meanwhile, Henrietta's family continued to live in poverty and frequently poor health, and their discovery decades later of her unknowing contribution--and her cells' strange survival--left them full of pride, anger, and suspicion.
For a decade, Skloot doggedly but compassionately gathered the threads of these stories, slowly gaining the trust of the family while helping them learn the truth about Henrietta, and with their aid she tells a rich and haunting story that asks the questions, Who owns our bodies? And who carries our memories?