MMP12 and pulmonary emphysema: Considering that the parenchymal fibers did not show functional effectiveness in respiratory mechanical maintenance after the remodeling process, this study could provide new clues to elucidate at which time points during emphysema development will be possible candidates to test new therapeutic strategies, considering the importance of collagenases (MMP-8 and -13) and metalloelastase MMP-12 in emphysema development.