The IGF-1 level increased significantly in osteosarcoma (624.3 ± 52.92), Ewing sarcoma (467.4 ± 18.80) and GCT (334.2 ± 31.17) groups compared to healthy controls (110.8 ± 28.18) (P < 0.0001); also patients with osteosarcoma produced a significant higher level of IGF-1 compared to patients with Ewing sarcoma (P=0.04) and GCT (P < 0.0001) (Figure 4B). Here, IGF1 is linked to osteosarcoma.