Song et al. reported that Vit C (100 mg/kg i.p.)protected cerebral ischemia-induced BBB disruption by preserving the expression of claudin 5 [71], whereas Lin et al. observed that Vit C (500 mg/kg i.p.)prevented compression-induced BBB disruption and sensory deficit by upregulating the expression of both occludin and claudin-5 [72]. The gene discussed is CLDN5; the disease is brain ischemia.