HK2 and diabetic retinopathy: Metabolic normalization represented a major therapeutic mechanism involved in the benefits observed with the iPSC cell combination, with coordinated suppression of glycolytic enzymes typically elevated in diabetic retinopathy, such as Hexokinase 2 (HK2), Pyruvate Kinase M2 (PKM2), Lactate Dehydrogenase A (LDHA), and Phosphoribosyl aminoimidazole Carboxylase/Synthetase (PAICS).