“…Despite these efforts, additional mechanisms of resistance to EGFR blockade are thought to be present in CRC and little is known about the determinants of sensitivity to this therapy [13,14,15,16]. Among them, it is important to mention Raf , PI3K , and MAP2K1 mutations, ERBB2 and MET amplification, low EGFR gene copy number, IGF1 overexpression, PTEN loss, over-activation of STAT3 by JAK, or mediated by nuclear PKM2 [5,6,9,10]. The latest evidences strongly suggest that complex molecular alterations coupled with changes in the tumor microenvironment may substantially contribute to the clinical efficacy of EGFR antagonists, even in CRC that are both KRAS and NRAS wild type [5,6,7,8,9,10,14].…”