Apart from PD-L1 level, other predictive biomarkers have been identified, including tumor mutational burden (TMB) (106), mismatch repair (MMR) deficiency (107), the status of tumor-infiltrating lymphocyte (TIL) (108), immunosuppressive cell populations (109), oncogenic driver mutations (110–112), neoantigen repertoire (113), gut microbiota (114–116), inflammation-related genes (117, 118), extracellular vesicles (119), and patient’s clinical characteristics (120). Here, CD274 is linked to neoplasm.