MMP7 and idiopathic pulmonary fibrosis: Circulating levels of MMPs 1, 3, 7, 8, and 9 have been shown to be elevated in patients with IPF [9, 11] and higher circulating levels of MMP7 to be associated with more severe disease [11], a higher risk of disease worsening over a 3-year period [12], and shorter survival time [13].