Henrietta Lacks was a poor, African American woman who died of cervical cancer at the age of 31. One of her doctors at Johns Hopkins University Hospital harvested cells from her which became the basis for an immortal line of cells used in medical research labs. Rebecca Skloot has tracked down the story of these so-called HeLa cells and told it in a book called "The Immortal Life of Henrietta Lacks." Skloot talks with Jim Fleming.