During this study, eligibility for anti-EGFR monoclonal antibody therapy (cetuximab or panitumumab) in CRC evolved from requiring wild-type KRAS to requiring wild-type RAS, necessitating mutation testing of NRAS in addition to KRAS. The only method of assessing NRAS status within our laboratory was the panel, and 51/88 (58.0%) patients with CRC were found to have tumours with wild-type RAS. The audit of subsequent clinical action revealed that 5/51 (9.8%) of these patients received anti-EGFR therapy (cetuximab). This evidence concerns the gene EGFR and colorectal carcinoma.