Hyperactivation of yes-associated protein-1 (Yap1) and transcriptional coactivator with PDZ-binding motif (Taz), due to a genetic depletion of Mps One Binder kinase activator (Mob)1a/1b in mouse liver, results in an increased incidence of combined HCC-CCA and iCCA. Here, YAP1 is linked to hepatocellular carcinoma.