PTEN and hepatocellular carcinoma: To clarify the potential oncogenic role of miR-21 in HCC development, we investigated herein the impact of miR-21 total (miR21KO mice) and/or hepatocyte-specific (LmiR21KO mice) genetic deletion in HCC development induced over one year after a single DEN injection, and the impact of hepatocyte-specific simultaneous deletion of the tumor suppressor PTEN and miR-21 (LPTENmiR21KO mice).