MEG3 and central nervous system cancer: Further, a study has found that the PIWIL1/piRNA-DQ593109 (piR-DQ593109) complex is a major regulator of blood-tumor barrier (BTB) permeability in glioma through the MEG3/miR-330-5p/RUNX3 axis, and their inhibitions could enhance efficient delivery of anti-glioma drugs to glioma tissues [192].