Mutation, e.g. to chromosome 5, Epithelium Further mutation, e. g, allele loss from produces a hyperpr chromosome 18, produces epithelial focus alargeadenoma mmucosa Further DNA alterations, e. g formation of as mall adenoma n0 Another mutation, e.g. allele loss from chromosome 7, leads to the abilityt om east h Further mutation, e.g. to ras gene, produces an intermediate adenoma Multi-step model of carcinogenesis of colon cancerMulti-step model of carcinogenesis of colon cancer