CD274 and neoplasm: Additionally, hypoxia leads to immunosuppressive cell types such as Tregs and MDSCs, M2-polarized tumor-associated macrophages (TAMs), helper T cells (TH)2-polarized dendritic cells (DCs), the downregulation of MHC class-I molecules and natural killer (NK) cell-activating ligands, and the upregulation of PD-L1 on tumor cells that combinatorial immunotherapy and SBRT can counter.