Steven Pete can put his hand on a hot stove or step on a piece of glass and not feel a thing, all because of a quirk in his genes. Only a few dozen people in the world share Pete's congenital insensitivity to pain. Drug companies see riches in his rare mutation. They also have their eye on people like Timothy Dreyer, 25, who has bones so dense he could walk away from accidents that would leave others with broken limbs. About 100 people have sclerosteosis, Dreyer's condition.

Both men's apparent superpowers come from exceedingly uncommon deviations in their DNA. They are genetic outliers, coveted by drug companies Amgen, Genentech, and others in search of drugs for some of the industry's biggest, most lucrative markets.

Their genes also have caused the two men enormous suffering. Pete's parents first realized something was wrong when, as a teething baby, their son almost chewed off his tongue. "That was a giant red flag," says Pete, now 34 and living in Kelso, Wash. It took doctors months to figure out he had congenital insensitivity to pain, caused by two different mutations, one inherited from each parent. On their own, the single mutations were benign; combined, they were harmful.