KDR and bone metastasis: To gain additional insight into the potential clinical relevance of targeting both VEGFR2 and c-MET in men with PC bone metastases, we tested the effect of axitinib (VEGFR inhibitor) [23] and crizotinib (c-MET inhibitor) [24], either as single agents or in combination, in an orthotopic bone metastasis model of PC in both intact and castrated NSG mice [25].