The relationship between IDH1 and survival. The IDH1 high expression group represents the osteosarcoma patients with >50% IDH1 positive staining. Patients with ≤ 50% IDH1 positive staining are recorded as low-expression group. The survival time in the χ -axis was given as years. There is no significant correlation between IDH1 expression and overall survival (P = 0.342).