Cetuximab (anti-EGFR) is used in combination with chemotherapy in refractory CRC disease; however, mutations in KRAS or BRAF lead to aberrant activation of mitogen-activated protein kinase (MAPK) signaling, thereby causing cetuximab resistance with limiting its clinical use to wild-type RAS/RAF tumors (33, 34). The gene discussed is EGFR; the disease is colorectal carcinoma.