KRAS and colon carcinoma: Epithelial malignancies have preferences for KRAS mutations among the three RAS genes, namely HRAS, NRAS, and KRAS; although KRAS mutation rate varies among tissues, it can be as high as ~90% in pancreatic cancer; 20–50% in carcinomas of the colon, lung, and hepatobiliary tract; and much less frequent in other carcinomas [3].