However, it is noteworthy that while these mutations can predict a negative response to therapy with anti-EGFR mAbs in some patients, objective responses of up to 44% have been reported in studies investigating mCRC patients with KRAS mutations treated with cetuximab, and only a 41% response rate is observed in patients with left-sided tumours [156,161]. The gene discussed is EGFR; the disease is neoplasm.