Alternatively, the expression of PD-L1 may depend on inflammatory signals, cytokines, and metabolites (i.e., IFN-α, TNF-α, IL-6) arising from the tumor cells themselves or from the TILs, the antigen-presenting cells (APC), and the tumor-associated macrophages (TAMs) (Zhang et al., 2017). The gene discussed is CD274; the disease is neoplasm.