Analysis of the correlation between HCC signature score, infiltration score, various immune cell infiltration, important immune checkpoints and IMPDH1 showed that high expression of IMPDH1 may increase CD8+T cell infiltration and the expression of immune checkpoints such as PD-1 and CTLA4, while targeting IMPDH1 might contribute to immunotherapy. The gene discussed is CD8A; the disease is hepatocellular carcinoma.