SOX9 and osteosarcoma: Multivariate Cox regression analysis enrolling above-mentioned significant parameters revealed that SOX9 expression (RR 6.9, 95% CI, 1.5-14.8 P < 0.001), clinical stage (RR 2.3, 95% CI, 1.1–7.0, P = 0.02), distant metastasis status (RR 3.7, 95% CI, 1.9–9.8, P = 0.01), and response to chemotherapy (RR 2.6, 95% CI, 1.5–8.2, P = 0.02) were independent prognostic markers for OS of patients with osteosarcoma (Table 2).