MMP2 and Alzheimer disease: In BLM-induced interstitial lung disease mouse models, pulmonary fibrosis showed improvement with AD-MSCs derived from young donor mice (4 months) but not with AD-MSCs derived from aged donor mice (22 months); the authors speculated that the difference in the anti-fibrotic effect of the AD-MSCs was due to the lower fibrotic MMP-2 levels in AD-MSCs from young mice compared with those from old donors [73].