Indeed, our work provides compelling evidence that overexpressed JAG1 could enhance ovarian cancer cell proliferation, whereas depletion of JAG1 by siRNAs or suppression of Notch1 signaling by γ-secretase inhibitor (GSI) could sensitize chemoresistant ovarian cancer cells to cisplatin-induced cytotoxicity by in vitro and in vivo models, suggesting that the JAG1-Notch1 signaling axis plays a critical role in the development of ovarian cancer chemoresistance. This evidence concerns the gene NOTCH1 and ovarian cancer.