Polymorphisms of eNOS[98], obesity-related genes (db/db and ob/ob)[99], TGF-β1 and -β2 stimulated clone-22 genes[100], have also been proposed to contribute to the development of D polymorphisms in erythropoietin[34], eNOS[20] and VEGF-A genes, and are considered important in the pathogenesis of DME. Here, NOS3 is linked to obesity due to melanocortin 4 receptor deficiency.