MMP9 and pulmonary emphysema: Furthermore, the results of mRNA expression determined by real-time PCR correlated with those seen by gelatine zymography suggesting that LGF could regulate the extracellular matrix destruction by promoting the upregulation of MMP inhibitors TIMP-1 and TIMP-2 and the downregulation of MMP-9 but not MMP-2, both involved in the development of emphysema.