I first met the writer Rebecca Skloot about eight years ago. She had been working on a book for a couple years and running late. The idea was brilliant, though, so I hoped she’d be able to get it done before too long. Many scientists who study human cell biology use a special line of cells known as HeLa. It came from a woman named Henrietta Lacks, who died of cervical cancer in 1951. Skloot was writing about Lacks, her family, and the way her body became dispersed around the world.

When I would see Skloot again, I’d ask how the book was going. Still going. After a while, I stopped asking, because I know how irritating that question can get