When Jeannie Peeper was a small child, doctors told her parents that her condition would kill her by the time she was a teenager. That was over 50 years ago. Peeper suffers from fibrodysplasia ossificans progressiva (FOP), a rare disorder that triggers the ossification (turn to bone) of muscles, tendons, and ligaments when they are damaged — essentially causing her to grow a second skeleton. Not wanting to be limited by the disease, Peeper has connected herself with more than 500 people with the disorder over the years, financing a new lab that allows medical experts to study cells and DNA to develop new ways of treating FOP. The Atlantic details Peeper's struggle with her condition, how researchers have pinpointed the genetic condition that causes it, and how FOP sufferers are aiding research by donating their blood, DNA, and even teeth.