CD274 and neoplasm: In this review, we grouped immune-related biomarkers into three categories: biomarkers of tumor immunogenicity (i.e., PD-L1, TMB, and microsatellite instability), biomarkers of the tumor immune microenvironment (i.e., tumor-infiltrating lymphocytes), and biomarkers of the host immune system (i.e., peripheral blood inflammatory markers and myeloid-derived suppressor cells).