STOCKHOLM, Sweden — Two Americans and a U.S.-based Japanese scientist won the Nobel Prize in chemistry for their discovery and development of a protein that literally illuminates key processes such as the spread of cancer inside living organisms.

Japan's Osamu Shimomura and Americans Martin Chalfie and Roger Tsien shared the prize for their work on green fluorescent protein, or GFP, which was first found in a jellyfish, the Royal Swedish Academy of Sciences said.