SMAD4 and cancer: A WES study demonstrated that the frequently mutated genes in OV-related ICCs comprise both known cancer genes, such as TP53, KRAS and SMAD4, and newly implicated cancer genes including MLL3, ROBO2, RNF43, PEG3, and GNAS, which are genes involved in histone methylation, genome stability, and G-protein signaling (Ong et al., 2012).