To reveal the importance of PLAGL2 in the anti‐HCC effect of SeS2, we measured PLAGL2 protein levels in SK‐Hep‐1 and SMMC‐7721 cells after treatment with SeS2 at different concentrations for 48 h or at 20 μM for different durations. Here, PLAGL2 is linked to hepatocellular carcinoma.