In this respect, we were specifically interested in the role of MMP-12, an important elastase secreted from macrophages, which has been shown to play diverse roles in inflammatory processes such as arthritis (Wang et al., 2004), atherosclerosis (Johnson et al., 2005; Liang et al., 2006), and AAA (Curci et al., 1998; Longo et al., 2005). The gene discussed is MMP12; the disease is Arthritis.