Wildtype mice do not express the ortholog of MMP-1 in lung and do not develop caseous necrosis or cavities in response to Mtb; in human MMP-1 transgenic mice, however, infection with TB leads to collagen destruction and caseous necrosis (Elkington P. et al., 2011; Al Shammari et al., 2015). This evidence concerns the gene MMP1 and infection.