VEGFA and neuromyelitis optica: Our previous studies demonstrated that sera from NMO spectrum disorder (NMOSD) patients induces BBB malfunction via the autocrine secretion of vascular endothelial growth factors (VEGF) and matrix metalloproteinase-2/9 by the microvascular endothelial cells of the brain (BMECs) [20,21], suggesting that a focal increase of the cytokines/chemokines around the BBB may be involved in the pathogenesis of NMO.