Retrospective analyses showed that tumour regression is more frequently observed among patients with increased EGFR gene copy number (Moroni et al, 2005; Sartore-Bianchi et al, 2007; Cappuzzo et al, 2008), while lack of response and short survival was observed in individuals harbouring a KRAS mutation (Lièvre et al, 2006, 2008; Di Fiore et al, 2007; Khambata-Ford et al, 2007; Amado et al, 2008; De Roock et al, 2008). This evidence concerns the gene EGFR and neoplasm.