More specifically, in the responder group, high PD-L1 expression was found in macrophages at the tumor–stroma interface, followed by a rapid decrease in expression within the tumor, with even higher PD-L1 expression in the vicinity of cytotoxic T cells, whereas in non-responders, PD-L1 expression and cytotoxic T-cell activation follow a more arbitrary spatial regulation [70]. The gene discussed is CD274; the disease is neoplasm.