Autophagy can also inhibit or promote tumor angiogenesis: The tumor suppressor gene PTEN inhibits neovascularization by inducing autophagy in mouse brain tumors, yet autophagy promotes the expression of the HMGB-1 protein, which is beneficial to angiogenesis and tumor cell survival in an anoxic microenvironment, as shown in Figure 3A [19,108,109]. Here, PTEN is linked to neoplasm.