TET1 and glioblastoma: Besides, GHB has also beenshown to stimulate GSC cell adherence and generation of membrane extensions.69 Moreover, PN glioblastoma cells have high expressionof TET1 and increased level of 5-hmC compared to mesenchymal cells,and TET1-mediated increase of 5-hmC is critical for PN cell tumorigenicity.70 Considering this, our finding of GHB enrichmentin PN sEVs might suggest that 5-hmC-dependent PN cells secrete GHB,a TET antagonizing metabolite, via sEVs not only to maintain theircellular characteristics and tumorigenicity but also to support theinvasive nature of surrounding MES cells.