TNFRSF1B and neoplasm: Because PD-1 reflects a dynamic status in T cell activation—first being up-regulated in activated T cells and then leading to immune suppression by binding to PD-L1 [56,57,58,59]—it is possible that CD8+ TNFR2+ PD-1+ TILs are activated/effector CD8+ cytotoxic T cells; this possibility is supported by recent studies that have identified CD8+ PD-1+ cells as immune-reactive TILs in TNBC and in additional tumor systems [54,60,61], as will be discussed further below.