KRAS mutation status has been shown to be a predictive factor for response to anti-EGFR monoclonal antibodies in metastatic colorectal cancer (Bokemeyer et al, 2009; Van Cutsem et al, 2009) and, recently, KRAS wild-type status has been recognised by the US FDA and EMEA as a predictive factor to select patients candidate to receive cetuximab or panitumumab. The gene discussed is KRAS; the disease is metastatic colorectal cancer.