CASP2 and hepatocellular carcinoma: While this feature can promote tumorigenesis in several mouse tumor models in the absence of caspase-2 (7–10, 19–22), there are also contradictory reports that increased hepatocyte polyploidy in Casp2−/− mice fosters protection against carcinogen (diethylnitrosamine)–induced HCC development (3, 22–24).