SMAD4 and pancreatic adenocarcinoma: Consistent with the potential cancer-specific role of the genes, some of them are much more frequently mutated in particular cancers, for example, SMAD4 in PAAD (22%), READ (16%), COAD (14%), and ESCA (8%); DICER1 in SKCM and UCEC (∼9%); TNRC6A in STAD (9%) and UCEC (7%); ZCCHC6 in ACC (6.5%); SMAD2 in COAD and READ (∼5%); and PRKRA in OV (4.3%).