PDC and Hyperglycemia: Although prior studies have demonstrated that TGFβ1 induces HIF1α stability under hypoxic and normoxic conditions by inhibiting the prolyl hydroxylase domain protein PHD2, an oxygen sensor that typically promotes HIF1α degradation [45], notably, the stability and function of HIF1α are also regulated by hyperglycemia through interference with the degradation of HIF1α triggered by PHD enzymes [46].