Number 23: Understanding cancer
Scientists long believed there was a link between human cancer and genes, but biologist Robert Weinberg, who in 1982 cofounded the Whitehead Institute at MIT, proved it by showing that bladder cancer in people was caused by the same genetic process as a genetically triggered cancer in rats. He also discovered the first gene known to turn off cancer, and he outlined the six hallmarks of all cancers, effectively establishing a common definition that could be shared by scientists across the world.