STAT3 and glioblastoma: Ispinesib is one such potent inhibitor and has been shown to prolong the survival of murine GBM models.19,20 Resistance to this class of inhibitors can occur through point mutations that block drug binding,21 upregulation of an alternative kinesin,22 upregulation of drug efflux transporters,20 upregulation of EGF (epidermal growth factor) to promote cell cycle progression,23 and activation of STAT3 (signal transducer and activator of transcription 3) to inhibit apoptosis.24