Topping the list of things most teenagers probably would not want for Christmas? A trip to the hospital. But 15-year-old Joshua Nienow didn’t have a choice. On December 19, 2002, hours after he was diagnosed with acute myeloid leukemia (AML), Joshua was admitted into Vanderbilt Children’s Hospital in Nashville, Tennessee to begin a yearlong battle against the disease. For the next nine weeks, he would endure several rounds of harsh chemotherapy treatment and a surgery to remove 12 inches of his intestines. To make matters worse, he already had Crohn’s disease, which complicated his treatment and made his outlook even...