IFNG and Ewing sarcoma: Patients with metastatic osteosarcoma tumors (0.65 ± 0.05) over-expressed IFN-γ compared to their non-metastatic counterparts (0.44 ± 0.02) (P = 0.001); while the difference in patients with Ewing sarcoma tumors as a matter of metastasis was not remarkable (Fig. 4E).