KRAS and colorectal carcinoma: The aims of this review are to: 1) systematically analyze current literature and perform a meta-analysis of the available data on the impact of key genetic variants in CRC-related genes (i.e., KRAS, NRAS, BRAF, SMAD4, PIK3CA) as prognostic markers in surgically treated metastatic CRC patients; and 2) explore the potential role of emerging biomarkers like HER2 and microsatellite instability (MSI) status in current and novel therapeutic strategies, including liver transplantation for LM.