A lot of medicine's direst emergencies come down to one problem: lack of oxygen.
Cardiologist John Kheir started thinking about that when a little girl in his care, drowning from lung hemorrhages, died before she could be hooked up to a heart-lung machine that would have kept her blood oxygenated while the damage was repaired.
When scientists were looking for the first person to test a new, superfast way of deciphering someone's entire genetic blueprint, they turned to James Watson – the guy who shared a Nobel Prize for discovering the structure of DNA.
"They had to sequence someone, so they got me," he says.
In the U.S., the pap smear has become a routine part of women's health care, and it's dramatically reduced cervical cancer deaths. But in Africa and other impoverished regions, few women get pap smears because the countries lack the laboratories and other resources necessary to offer them.