The TME has been divided into four different types based on PD-L1 expression and CD8+ tumor-infiltrating lymphocytes (TILs); type I (PD-L1 positive with TILs driving adaptive immune resistance), type II (PD-L1 negative with no TIL indicating immune ignorance), type III (PD-L1 positive with no TIL indicating intrinsic induction), and type IV (PD-L1 negative with TIL indicating the role of other suppressor in promoting immune tolerance) [3]. The gene discussed is CD8A; the disease is neoplasm.