However, clinical trials in osteosarcoma have demonstrated the low efficacy of single-target therapy by inhibiting VEGFs (by bevacizumab) (80), KIT and PDGFRα (by imatinib) (115), and IGF-1R (by cixutumumab or R1507) (Figure 3) (144, 145). Here, PDGFRA is linked to osteosarcoma.