The promise of genetic medicine is beginning to be fulfilled, but it's been a long, hard slog.
Take the story of Kalydeco. It's designed to treat people with a lung disease called cystic fibrosis. While not quite a cure, the drug is extremely effective for some CF patients.
But the success of Kalydeco has been more than two decades in the making.
Katie Alonzo was stunned when doctors told her they couldn't get a drug her 10-year-old daughter, Abby, was taking to fight lymphoma.
"When a doctor says, 'This is what you need to take.' And then all of a sudden somebody tells you, 'Well, that is what you need to take but this isn't available so we're going to try this instead,' it's very scary," say Alonzo, who lives in Port St. Lucie, Fla.
Niacin, a B vitamin that raises "good" cholesterol, has failed to benefit heart disease patients when taken in tandem with a statin drug that lowers "bad" cholesterol, according to drug maker Merck.