SMAD4 and carcinoma of the ampulla of vater: Tumor protein 53 (TP53), Kirsten rat sarcoma virus protein (KRAS), breast cancer type 1 and 2 susceptibility proteins (BRCA1/2), mothers against decapentaplegic homolog 4 (SMAD4), and microsatellite instability-related molecular alterations are described in ampullary carcinomas, and these also seem to correlate with histological subtypes, i.e., pancreatobiliary and intestinal [11].