However, with high heterogeneity and risk of bias together with low applicability concern we need additional pragmatic designed research to back up its use in screening and diagnostic applications.<h4>Conclusion</h4>Within the limitations of the study, salivary MMP-9 has merit as a biomarker for identification of early-stage (I, II) oral cancer. The gene discussed is MMP9; the disease is lip and oral cavity carcinoma.