An earlier analysis of data from the present study showed a higher incidence of skin toxicity in patients with KRAS WT tumours than in those with KRAS MT tumours (Thaler et al, 2012), which may reflect the higher mean cumulative panitumumab dose and longer duration of treatment (i.e., panitumumab cycles) received by the KRAS WT group. This evidence concerns the gene KRAS and neoplasm.