STAT3 and cancer: Drug-induced stabilization of the tumor cells’ interphase microtubules, as evidenced by an increase in microtubule polymer mass resulting in bundling, was observed upon treatment with both paclitaxel and the combination; however, honokiol alone was not effective in the formation of microtubule bundles (Fig. 5d). Collectively, these data indicate that honokiol enhances the in vitro cytotoxicity of paclitaxel in MDR cancers, may be through the inhibition of EGFR-STAT3 survival signaling.