JAG1 and neoplasm: Clinically, high NOTCH2 expression in ovarian tumors was associated with recurrence and shorter progression-free survival of ovarian cancer patients.<h4>Conclusions</h4>Paclitaxel-induced translational upregulation of NOTCH2 enables immediate juxtacrine activation by JAG1-positive macrophages, coupling tumor cell survival with immune remodeling in the tumor microenvironment to drive chemoresistance.