Based on the presence or absence of tumor-infiltrating lymphocytes (TILs) and PD-L1 expression, four tumor immune microenvironment types have been proposed [9], including type I (TILs+ PD-L1+ associated with adaptive immune resistance), type II (TILs− PD-L1− indicating immune ignorance), type III (TILs− PD-L1+ indicating intrinsic induction) and type IV (TILs+ PD-L1− indicating other suppressors promoting immune tolerance). The gene discussed is CD274; the disease is neoplasm.