NFKB1 and obesity due to melanocortin 4 receptor deficiency: Studies have shown that high blood glucose levels as well as severe insulin resistance and obesity activate high NF-kB expression in retinal vascular cells and increase retinal inflammation and oxidative stress, but the latter two do not exhibit DR-specific vasculopathy, and that diabetes or hyperglycemia activates pathways such as NF-κB, inflammation, or oxidative stress leading to retinal capillary dysfunction, which indirectly suggests that hyperglycemia plays a crucial role in the progression of DR [6].