NRAS and neoplasm: Some biochemical (i.e., carcinoembryonic antigen, carbohydrate antigen 19-9 and 125) [24,25] and clinical (i.e., primary tumor site) [14,26] parameters as well tumor features (i.e., RAS, NRAS, and BRAF mutations; microsatellite instability/mismatch repair status) [14,15,16] have been reported to play a role in predicting efficacy and patients’ prognosis after the combination of FOLFIRI with targeted agents.