MMP12 and pulmonary emphysema: Other laboratories have built upon the MMP-12 work, documenting the importance of additional MMPs in emphysema pathogenesis (Shapiro et al., 2003; Seagrave et al., 2004; March et al., 2006; Valenca et al., 2006; Foronjy et al., 2008; Vecchio et al., 2010).