KRAS and cancer: CRC is considered a model of choice for cancer chemoprevention studies for two reasons: First, the molecular history of CRC is well established and involves early mutations in the adenomatous polyposis coli (APC) gene linked to hyperplasia followed by mutations in oncogenes and tumor repressors as in c-myc, K-ras, and p53 that lead to adenoma, adenocarcinoma, and carcinoma [2].