Colorectal cancer has for more than two decades served as the paradigm for the multi-step concept of cancer initiation and progression. Perhaps more than any other organ site, cancer of the colon is extensively characterized at the molecular level. We are now entering a time when molecular classification, rather than histologic classification, of cancer subtypes is driving the development of clinical trials with emerging targeted therapies. The book will focus on the progression from the identification of mutations that drive colorectal cancer initiation and progression to the search for novel therapies to treat the disease.