HMOX1 and Hyperglycemia: As a neuroprotective protein, transforming growth factor-β (TGF-β) overregulates hyperglycemia to protect RGCs from harm by activating stress response proteins and antioxidant pathways, such as aldehyde dehydrogenase 3A1, heme oxygenase-1 (HO-1), hypoxia-inducible factor (HIF) -1α, and nuclear factor erythroid 2-related factor (Nrf2) (Chen et al., 2020).