MMP2 and pulmonary emphysema: NF-κB pathway inhibited by SN50 results in decreased expression of CTSB and MMP-2, and NE has been shown to induce IL-8, CTSB, and MMP-2 production via the interleukin-1 receptor associated kinase-1/Toll-like receptor-4-mediated macrophage pathway 79, which leads to degradation of ECM, followed by emphysema common in lung diseases.