Tsien shares the prize with two other scientists. They're being honored for their discovery of Green Fluorescent Protein (GFP) and their work designing fluorescent molecules used to light up the inner workings of cells.
According to Tsien's academic biography, he was often kept indoors as a child because he suffered from asthma. He spent hours conducting chemistry experiments in his basement laboratory, and won first prize in the Westinghouse talent search at age 16.