CD274 and neoplasm: IFN-γ uses multiple pathways to induce PD-L1 expression in different tumor types, including JAK2/STAT1/IFR-1 pathways in gastric cancer, JAK/STAT3 and PI3K-AKT pathways in lung cancer, and MyD88-, TRAF6-, and MEK-dependent pathways in myeloma (197–199).