We found thatHGF, VEGF, zonulin and PGE2 in the absence of EGF in glioma C6 CM induced transmigration,that VEGF, zonulin and PGE2 opened the BBB, that ReNcells CX expressed CRTAM, occludinand claudins 1, 3 and 4 that might facilitate their paracellular migration and that at the sites oftransmigration the expression of occludin and claudin-5 diminished in brain endothelialmonolayers. The gene discussed is CLDN1; the disease is central nervous system cancer.