Plasma concentration of MMP-1, MMP-7 (Figure 1), MMP-9 and the MMP-9/TIMP-1 complex (Figure 2) showed a significant increase both in tobacco smokers and BE groups in comparison with the NS control group; however, no significant differences were found among the COPD groups (Table 2). This evidence concerns the gene TIMP1 and chronic obstructive pulmonary disease.