CD8A and neoplasm: The hypoxic response is also recognized to upregulate VEGF-A which not only promotes angiogenesis and formation of new vessels that are abnormal in structure, that contributes to ischemia from poor blood flow and the subsequent the tumour hypoxic microenvironment [46], but also may further augment the immunosuppressive tumour microenvironment in TNBC as it also mediates T cell exhaustion by increasing PD-1 expression on CD8+ T cells [41, 47].