CD8A and neoplasm: Previous studies have identified various biomarkers related to immunotherapy prognosis, including tumor characteristics (PD-1/PD-L1 expression 23, TMB 24), tumor microenvironment (CD3/CD8 tumor-infiltrating lymphocytes 25, dMMR/MSI 26), peripheral blood markers (NLR/PLR 27, ctDNA 28 ALFP score 29), and gut microbiota 30.