KRAS and colorectal neoplasm: Therefore, although the therapeutic benefit of EGFR-targeted therapy in colorectal tumours has been clearly established (Cunningham et al, 2004; Saltz et al, 2004; de Castro-Carpeno et al, 2008), response is preferentially observed in tumours without mutations in K-Ras, whereas patients with tumours carrying K-Ras mutations have response rates below 10% (Lièvre et al, 2006; Di Fiore et al, 2007; Hecht et al, 2007; Amado et al, 2008; De Roock et al, 2008; Karapetis et al, 2008; Lievre et al, 2008; Allegra et al, 2009; Bokemeyer et al, 2009).