The exome analysis of a wide group of CRC patients undergoing EGFR blockade showed additional mechanisms of resistance in addition to those commonly reported, including mutations other than those commonly reported, such as mutations of ERBB2, EGFR, FGFR1, PDGFRA and MAP2K1; furthermore, amplifications and mutations in the tyrosine kinase receptor adaptor gene IRS2 have been identified in tumors displaying sensitivity to EGFR blockade [153]. Here, ERBB2 is linked to colorectal carcinoma.