Though Skloot becomes part of the story, her focus is always on telling the story of Henrietta and her family; she considers the book a biography of Henrietta and a biography of her cells. But it's also some serious science writing. There's a ton of information about cell cultures, genetics, and cancer and other diseases. She covers questions like patient privacy and informed consent, unethical research, exploitation of vulnerable patients, and racial disparities in access to medical care.
Keeping the family at the center makes these issues seem very real. We don't have to be lectured about the dangers of being uninsured; we see Sonny wake up six figures in debt after surgery.