It has been shown in a diabetic retinopathy model that GFAP overexpression is also an early feature of glial reactivity leading to morphological and structural changes, such as overexpression of the water transport channel aquaporin 4 inducing retinal edema [40], secretion of cytokines and inflammatory factors damaging the BRB [41], and production of VEGF that in turn increases capillary permeability, vascular leakage and promotes neovascularization [42]. Here, AQP4 is linked to diabetic retinopathy.