CD47 and neoplasm: Our analyses further revealed that hypoxia increases the expression of several immune checkpoints including PD1, PDL1, PDL2, CTLA4, TIM3, CD47, B7-H3, VISTA, VTCN1, CD70, and LAG3. In related studies, hypoxia significantly increased the expression of PD-L1 on DCs, macrophages and tumor cells, and induced the apoptosis of T cells (Noman et al., 2014).