• Lower occludin levels observed in Multiple Sclerosis • VEGF mediated phosphorylation of occludin in Diabetic Retinopathy leads to dysfunctional iBRB • Alzheimer’s disease found increased amyloid-β clearance into blood when claudin-5 and occludin down-regulated. The gene discussed is VEGFA; the disease is early-onset autosomal dominant Alzheimer disease.