Moreover, the significant antitumor efficacy of new tyrosine kinase inhibitor (TKI) XL-184 (cabozantinib maleate), which targets MET and VEGFR-2, for bone metastasis in patients with prostate or breast cancers also shows the importance of HGF/MET signaling in bone metastasis [9, 18]. Here, KDR is linked to breast cancer.