SMAD4 and cholangiocarcinoma: In this research, the genomes of patients with cholangiocarcinoma’s, comprising 152 intrahepatic and 43 extrahepatic cases, from Caucasian, Asian, and African American populations, revealed that the most prevalent mutations were in IDH1, TP53, ARID1A, BAP1, KRAS, PBRM1, SMAD4, and ATM.28