Scientists have long puzzled over the different fates of identical twins: both have the same genes, yet only one may develop a serious disease like cancer or autism. What's going on? Does something else besides genes determine who we are? NOVA explores this startling possibility in this program.
Explore all movies including trending, top rated, and upcoming releases
Browse popular TV shows, top rated series, and shows airing today
Discover content from Netflix, HBO, Disney+ and other streaming platforms
Discover actors, directors, and other film industry professionals