STAT3 and glioblastoma: STAT3 has been characterized as one of the major drivers of GBM, contributing to the maintenance of stemness and a mesenchymal phenotype via the IL-6/glycoprotein 130 (GP130)/STAT3 or EGF receptor (EGFR)/JAK2/STAT3 axis and leading to chemo- and radiation resistance of the tumor [43–45].