PSMB9 and hepatocellular carcinoma: It has been found that four coexpression genes (GZMA, C1QC, CD3D, and PSMB9) have been identified as CD8+ T cell coexpression genes that promote CD8+ T cell infiltration in HCC, and these coexpressed genes are favorably associated with the infiltration of CD8+ T lymphocytes during antigen presentation.