KRAS and colorectal carcinoma: While KRAS-G12 mutations are frequent in pancreatic (91% of KRAS-mutated cases), colorectal (CRC) (68%), and lung (85%) cancers, KRAS-G13 mutations are common in gastrointestinal cancers (20% in CRC), and KRAS-Q61 alterations are common in human melanomas (85%) [9,16].