Our in vitro functional results revealed that KIF20A silence attenuated the proliferation and increased capsase-3 and -9 activities of HCC cells, consistent with studies showing that KIF20A promoted cell proliferation in pancreatic [35], ovarian [36], bladder [37] and lung cancer [38]; caspase-3 and -9 are two key mediators in the apoptotic signaling pathways, and our results may imply that KIF20A knockdown repressed HCC cell proliferation cells via enhancing activities of cell apoptotic signaling pathway. The gene discussed is CASP3; the disease is lung carcinoma.