Inactivation of the Hippo pathway in murine liver through deletion of the serine-threonine protein kinases mst1 and mst2 or their adapter protein sav1/WW45 increased liver size and hepatocyte proliferation, and resulted in the development of HCC and iCCA [78], or formation of hepatomas positive for oval cell marker A6 [79]. The gene discussed is MST1; the disease is hepatocellular carcinoma.