STAT3 and glioblastoma: It has been revealed that circular E-cadherin (circ-E-Cad), which encodes the oncogenic variant of E-cadherin, is significantly overexpressed in GBM and activates the EGFR (in the absence of EGF) through the EGFR–STAT3 signaling, resulting in the maintenance of GSCs properties and the promotion of GBM tumorigenicity [202].