KRAS and colorectal carcinoma: Several predictive biomarkers have emerged to aid in the therapeutic decision-making in metastatic CRC, such as KRAS (40%), NRAS (5–10%), and BRAF (8–10%) mutation status, tumor sidedness, microsatellite instability (MSI), and other less common alterations such as HER2 (2%), MET (2%), NTRK (0.2-2.4%), ALK (0.2–2.4%), and ROS1 (0.2–2.4%) [6].