Single-cell RNA sequencing analysis of WT and Lrg1−/− mouse brain tissues after cerebral ischemia‒reperfusion injury revealed that Lrg1 knockout enhances blood‒brain barrier (BBB) by upregulating claudin 11, integrin β5, protocadherin 9, and annexin A2. This evidence concerns the gene CLDN11 and Cerebral ischemia.