These cells have been shown to be elevated in asthma and chronic obstructive pulmonary disease (COPD) [26], as well as in IPF, where MMP1, MMP2 and MMP9 were shown to be co-localized to the epithelium surrounding fibrotic lesions, while increased TIMP2, was also observed suggesting that the MMP activity may be inhibited and that the fibrotic region is not degraded [27]. Here, TIMP2 is linked to chronic obstructive pulmonary disease.