The results indicated that EFNA3 and EFNA4 were significantly related to some immune-related genes, TMB, and MSI in HCC; EFNB1 was positively associated with most immune-related genes, such as PD-1, CTLA4, PD-L1, and PD-L2, but unrelated to TMB and MSI scores. The gene discussed is PDCD1; the disease is hepatocellular carcinoma.