Anti-EGFR therapies, specifically anti-EGFR monoclonal antibodies such as cetuximab and panitumumab, combined with chemotherapy have resulted in a survival benefit for patients with left-sided metastatic colorectal cancer (mCRC) with RAS/RAF wildtype tumors (Heinemann et al., 2014; Venook et al., 2017; Yoshino et al., 2022). This evidence concerns the gene EGFR and metastatic colorectal cancer.