The significant over-representation of k-ras G : C → T : A transversions in MYH polyposis tumours as compared to sporadic and FAP-associated colorectal tumours is consistent with the mutational mechanism of MYH-associated tumorigenesis revealed in our previous studies (Al-Tassan et al, 2002; Jones et al, 2002). This evidence concerns the gene KRAS and neoplasm.