CD274 and neoplasm: For instance, hypoxia has demonstrated to promote the release of immunosuppressive cytokines such as interleukin-10 and TGF-ß, to increase the expression of the programmed cell death ligand, PD-L1 both on immune cells and tumor cells, and to elevate the number of immunosuppressive immune cells including regulatory T cells, myeloid derived suppressor cells and tumor-associated macrophages 23-25.