Liu et al (36) found that ischemia triggers 2 rapid and parallel processes that cause the early disruption of the BBB: matrix metalloproteinase-2 (MMP-2)-mediated occludin degradation and caveolin-1 (Cav-1)-mediated redistribution of claudin-5 from the cytoskeleton to the cytosol in the ischemic cerebral microvessels. The gene discussed is MMP2; the disease is ischemia.