KRAS and adenoma: Using this approach, they demonstrated that three main molecularly-distinct subtypes can be recognized: (i) the first subgroup (CCS1-CIN) is typically associated with KRAS and TP53 mutations and represents the group of chromosomal-instable tumors; (ii) the second group (CCS2-MSI) was strongly associated with MSI and CIMP; and (iii) the third subtype (CCS3-serrated) is heterogeneous for the MSI and CIMP status and relates to the sessile-serrate adenomas and shows the upregulation of the genes involved in matrix remodeling and the epithelial–mesenchymal transition [249].