In this analysis, pooled sensitivity, pooled specificity and DOR of MMP-9 for osteosarcoma were found to be 0.78 (95% confidence interval CI: 0.730–0.83), 0.90 (95% CI: 0.79–0.95) and 31.20 (95% CI: 11.97–81.31), respectively [101]. The gene discussed is MMP9; the disease is osteosarcoma.