GNAS and cancer: In the adenomas of group 2 and 3, no additional mutations at the level of other cancer driver genes were identified; in contrast, in the adenomas with APC mutations additional cancer driver genes (such as KRAS, NRAS, TP53, GNAS, AKT1, ARID1A and SOX9) were observed, whose number correlated with the degree of dysplasia and invasiveness.