In the presence of anti‐CD137 mAb and anti‐CD3 mAb, T cells cocultured with HCC‐827 cells produced extremely low levels of IFN‐γ (3.52 ± 0.71 pg/mL) (P < 0.05) (Fig 5(a)). This evidence concerns the gene TNFRSF9 and hepatocellular carcinoma.