UNC5B and multiple sclerosis: Conversely, our data also raise the possibility that intravenous injection of Netrin-1 could increase Wnt/β-catenin signaling at the BBB and repair CNS endothelial barrier breakdown in conditions such as multiple sclerosis or ischemic stroke where Netrin-1, Unc5B and several Wnt/β-catenin target genes are downregulated59.