Cldn3, Cldn5, and ZO-1 showed junctional localization in vessels of Wnt1-expressing GL261 gliomas. (A) IF staining for CD31/PECAM and Cldn3 on GL261 glioma and normal brain sections. Arrowheads indicate junctional localization. (B) IF staining for Cldn5 and ZO-1 on cryosections of GL261 brain tumors and normal brain. Bars: (A and B, tunors) 33 µm; (A and B, normal brain) 10 µm.