CD274 and neoplasm: Nakanishi et al. (2007) found that tumors with a higher level of PD-L1 were more likely to be considered high WHO grade. De Palma et al. (2008) reported that the immune treatment with IFN-α has yielded favorable outcomes in patients with melanoma. IFN-α promotes inflammatory environment, stimulates macrophages toward an M1 type, and hampers tumor growth and metastasis. Fiszer-Maliszewska et al. (1998) indicated that IL-2 could regulate adaptive immune response and increase infiltration of CD8+ T cells, further inhibiting tumor growth.