HIF1A and Hyperglycemia: Furthermore, cotreatment with Hcy, as described previously53, further increased HIF-1α levels in hyperglycemia-induced HUVECs compared to Set7_1a alone, demonstrating that Hcy could enhance the potency of Set7_1a to induce the stabilization of HIF-1α but not affecting the level of SET7/9 (Fig. 3c and Supplementary Fig. 8).