The analysis of a large set of data derived from randomized clinical trials allowed several important conclusions to be reached: (i) the addition of EGFR Mab to either chemotherapy or best supportive care improved PFS, OS and tumor response in KRAS-WT metastatic colorectal cancer patients; (ii) the use of EGF TKIs was without clinical benefit in KRAS-mutant metastatic colorectal cancer patients; and (iii) EGFR Mab, combined with Bevacizumab, is of no clinical value [494]. This evidence concerns the gene KRAS and metastatic colorectal cancer.