KRAS and head and neck carcinoma: KRAS is the second most commonly mutated gene, occurring frequently (> 10%) in most cancer types (pancreatic: 74.6%, colon cancer:44.24%, non-small cell lung cancer:30.93%) except hepatobiliary carcinoma, cervical cancer, bladder cancer, thyroid cancer, melanoma, small-cell lung cancer, head and neck carcinoma, prostate and breast cancer (Fig. 5B).