CPN1 and glioblastoma: Analysis of protein expression levels in U251 cells treated with HA-CPNs in the presence or absence of CME inhibitor, Endosidin9, not only confirmed the previously observed significant decrease of CD44 and CD44-ICD levels in cells treated with HA-CPNs in comparison to HA-CPN vehicle control but also demonstrated the decrease was rescued in cells treated with Endosidin9 (Fig. 5D), suggesting that CME plays an important role in the HA-CPN mediated effects in glioblastoma.