Tiny machines

ON A SHELF in Crystal Mackall’s office at Stanford University in Palo Alto, California, alongside a window that looks out on a lovely California scrub scape, is a teddy bear that once belonged to a boy named Sam*. Sam, who Mackall treated at the National Cancer Institute more than ten years ago, had Ewing’s sarcoma, a rare cancer that usually affects children and grows in or around bones.

Mackall is a paediatric oncologist with a dark blonde bob and a wry, take-noprisoners sense of humour. She has worked on cancer since the 1980s, so she has met a lot of very, very sick children. The way Mackall tells the story of Sam, like she’s taking a shot of foul-tasting medicine, you can see the distance she’s had to put between her emotions and her work. “We lost Sam. He was ten,” she says. “We gave him immunotherapy and it didn’t work.”

With that, Mackall moves on