JAG1 and breast cancer: The expression of JAG1 in bone-tropic breast cancer cells and the described promotion of osteolytic bone metastasis via activation of the Notch pathway in the bone microenvironment further support the role of ZEB1 in bone metastasis, as we recently showed that ZEB1 stimulates expression of JAG1 and subsequent activation of Notch-signaling through downregulation of miR-200 family members [46, 47].