Maria Sharapova returns the ball during the semifinals of the French Open on June 5. She used platelet-rich plasma to treat a shoulder injury. Miguel Medina/AFP/Getty Images hide caption

itoggle caption Miguel Medina/AFP/Getty Images

Ralph Thomas plays the harp at his house in Arlington, Vt. His reflux symptoms weren't controlled by medication, so he decided to have surgery to install a LINX device. Herb Swanson for NPR hide caption

itoggle caption Herb Swanson for NPR

Walter Bianco's liver is severely damaged by hepatitis C, but insurers had refused to pay for the medications that could cure him. Alexandra Olgin for NPR hide caption

itoggle caption Alexandra Olgin for NPR

TV host Samantha Harris says she will have a double mastectomy after being diagnosed with breast cancer. But the surgery doesn't eliminate cancer risk. Jordan Strauss/Invision/AP hide caption

itoggle caption Jordan Strauss/Invision/AP

I'm not trying to lead you astray. It's just that scientists are not skeptical enough about their mouse studies. iStockphoto hide caption

itoggle caption iStockphoto