TNF and type 2 diabetes mellitus: Even diabetic retinopathy, a retinal degenerative disease which can have no genetic component if associated with type 2 diabetes, has been shown in multiple studies to result in proinflammatory cytokines and chemokines such as TNFα, monocyte chemoattractant protein-1 and transforming growth factor-β to be secreted and microglial activation/infiltration of bloodborne macrophages into the retina from vascular leakage [31,32,33,34].