NPAS2 and hepatocellular carcinoma: Our data showed that HLE cells with NPAS2 knockdown exhibited a significant accumulation in G1 phase and a remarkable decrease in S phases, whereas NPAS2 overexpression significantly decreased the percentage of HLF cells in G1 phase and increased that in S phase (Figure 6a and Supplementary Figure S4A), suggesting that NPAS2 promotes S phase entry in HCC cells.