PCDH9 and glioblastoma: Wu et al. found that the miR-155HG–miR-155 axis plays a critical role in ME transition progression by regulating PCDH9 (protocadherin 9) and PCDH7, which play a pivotal role in glioma by suppressing the Wnt–β-catenin pathway, and serves as a prognostic factor of survival in GBM [29].