MMP2 and idiopathic pulmonary fibrosis: Matsuyama et al. demonstrated that HTLV-I positive patients with cryptogenic fibrosing alveolitis (CFA) significantly increased MMP-2 level in bronchoalveolar lavage fluid (BALF) as compared to HTLV-I negative patients, and no differences in the TIMP-2, indicating that the imbalance of MMPs and TIMPs maybe the cause of HTLV-induced pulmonary fibrosis.