Finally, piR-DQ590027 is poorly expressed in glioma-conditioned ECs whereas piR-DQ590027 over-expression could decrease ZO-1, occludin, and claudin-5 expression to further increase glioma-conditioned normal BBB permeability through the piR-DQ590027/MIR17HG/miR-153(miR-377)/FOXR2 pathway. Here, CLDN5 is linked to central nervous system cancer.