The high homology of CtBP1 and CtBP2 led us to speculate that NSM00158 could also target CtBP1, and our results confirmed that NSM00158 targeted CtBP1 and inhibited the transactivation of MDR1, thereby increasing the chemosensitivity of osteosarcoma CSCs. Here, CTBP2 is linked to osteosarcoma.