However, there remains considerable variability in the clinical response of CRC patients to EGFR inhibition (EGFRi) despite wild-type KRAS or EGFR status, meaning additional factors can dictate EGFRi sensitivity (Blanke, 2005; Jimeno et al, 2009; Shaib et al, 2013). This evidence concerns the gene EGFR and colorectal carcinoma.