Considering that deregulated growth could be caused by uncontrolled proliferation and resistance to apoptosis, we evaluated the effect of NPAS2 on the ability of proliferation in HCC cells and found that EdU (5-ethynyl-2'-deoxyuridine) incorporation was significantly decreased in HLE cells with NPAS2 knockdown when compared with control cells, whereas the forced expression of NPAS2 in HLF cells exhibited an opposite effect (Figure 2c). This evidence concerns the gene NPAS2 and hepatocellular carcinoma.