Based on FIRE-3 and CALGB/SWOG 80405 phase III trials, guidelines propose, as the main treatment option in first-line RAS/BRAF wild-type (WT) non-resectable metastatic colorectal cancer (mCRC), 5FU-based doublet chemotherapy with oxaliplatin (FOLFOX) or irinotecan (FOLFIRI), in combination with either an anti-epidermal growth factor receptor monoclonal antibody (anti-EGFR), cetuximab or panitumumab, or an anti-vascular endothelial growth factor monoclonal antibody (anti-VEGF), bevacizumab [2,3,4]. This evidence concerns the gene VEGFA and metastatic colorectal cancer.