It is observed in goblet-cell HPs [85] which rarely undergo malignant transformation; however, its presence, albeit less frequently, in advanced serrated polyps [84], in rare contiguous serrated polyps attached to population CRC (Young, unpublished observations) and in the lesions present in biallelic mutation carriers for MUTYH [90], suggests that serrated lesions with KRAS mutations are not completely devoid of malignant potential. This evidence concerns the gene KRAS and colorectal carcinoma.