Circular RNA DLGAP4 (circDLGAP4) has been found to significantly decrease in the plasma of ischemic stroke patients and in a mouse stroke model, and upregulation of circDLGAP4 expression significantly attenuated neurological deficits and decreased infarct areas and BBB damage, including reduced Evans blue extravasation, ameliorated the downregulation of tight junction proteins claudin-5, occludin, and ZO-1 [63]. The gene discussed is CLDN5; the disease is ischemic stroke.