Herein, we investigated the possible roles of 13 core circadian clock genes in HCC, including ARNTL, CLOCK, CRY1, CRY2, DBP, NR1D1, NR1D2, NPAS2, PER1, PER2, PER3, RORA, and TIMELESS. Here, PER3 is linked to hepatocellular carcinoma.