IL2 and cancer: The increased expression of CD39 and CD73 in various types of cancer is positively correlated with increased expression of hypoxia-inducible factor-1 (HIF-1) and the presence of some proinflammatory cytokines, such as tumor necrosis factor (TNF-α), interleukin-2 (IL-2), and interleukin-6 (IL-6), in the TME [11,12].