JAK2 and breast cancer: Our previous study demonstrated that leptin promoted PLOD2-mediated breast cancer metastasis via the activation of PI3K/AKT and JAK/STAT3 signaling pathways, while ruxolitinib (a selective inhibitor of JAK1 and JAK2) and LY294002 (an inhibitor of PI3Ks) reversed leptin-induced activation of these signals [16].