TOP2B and gastric cancer: Concerning miR-23a in chemoresistance, miR-23a has already been reported as having pivotal functions in the chemoresistance to cisplatin in TSCC [56] and ovarian cancer [53] through inhibiting TOP2B which is a target of miR-23a and functions as the target for several anticancer agents [56], and to paclitaxel in gastric cancer through the suppression of paclitaxel-induced apoptosis by targeting IRF1 at the post-transcriptional level [59].