MMP9 and neoplasm: Tu et al reported that no strong correlation of the MMP-9 expression is closely involved in tumour invasiveness and the prognosis of head and neck malignancies and that functional MMP-9 -1562 C>T polymorphism in the MMP-9 promoter with the risk of either is associated with OSCC or OSMF in male risk only in younger areca chewers [63].