We tend to think of innovation as a moment of epiphany followed by an onward march toward disruption. Sure, there are always some twists and turns along the way, but fearless entrepreneurs seem to have no problem adapting, iterating and pivoting their way to incredible success. That makes for inspiring stories, but the truth is that innovation more often follows a long and twisted path. Chief among the difficulties is the wide chasm-often known as the Valley of Death-that separates the discovery of important new insights and the development of a viable product. Many promising ideas never make it through. That’s one of the things that makes James Allison’s development of Cancer Immunotherapy so