The addition of cetuximab to doublet chemotherapy regimens such as FOLFIRI (5-FU, FA, CPT-11) or FOLFOX (5-FU, FA, L-OHP) has been shown to increase response rates, and prolong progression-free survival (PFS) and overall survival (OS) times in the first-line treatment of patients with metastatic CRC and KRAS wild-type tumours (Bokemeyer et al, 2009; Van Cutsem et al, 2009). The gene discussed is KRAS; the disease is neoplasm.