Global deletion of HDAC3 causes embryoni lethality of mice; cardiac-specific deletion of HDAC3 shows only 3−4 months survival of mice accompanying with cardiac metabolic disorder and mitochondrial dysfunction Represses hepatocellular carcinoma (HCC), multiple myeloma (MM) proliferation and growth Induces genome instability, cell cycle arrest and apoptosis Disrupts DNA damage repair in HCC Affects T cell maturation Represses prostate tumorigenesis and progression Stimulates rhabdomyosarcoma differentiation and limits tumor growth in presence of tamoxifen Represses inflammatory response. Here, HDAC3 is linked to hepatocellular carcinoma.