HIF1A and neoplasm: Hypoxia induced an increase in the production of the immunosuppressive cytokines by the gCSCs such as galectin-3 and VEGF, regulatory T cell and macrophage chemoattractants sCSF-1 [19] and CCL-2 [21], [57], and HIF-1α [10] but the gCSC is unlikely to be the sole source of these cytokines within the tumor microenvironment.