https://apnews.com/7bb38e71a15c83c84f201a0fa19b0a3d

In 2010, doctors treated Doug Olson’s leukemia with an experimental gene therapy that transformed some of his blood cells into cancer killers. More than a decade later, there's no sign of cancer in his body.

The treatment cured Olson and a second patient, according to the University of Pennsylvania doctors, who said it was the first time the therapy had been studied for so long.