Leukemia survivors reunite at medical school and 102-year-old shines on baseball diamond

In this "Dear David" episode, David Begnaud shares three inspiring stories: childhood leukemia survivors Ellie Koerner and Dawson Nailor reuniting in medical school, a routine hair appointment that turned into a life-changing cancer discovery, and 102-year-old Beatrice Stieber's first pitch at Wrigley Field.