MMP2 and pulmonary fibrosis: Preclinical studies of KITCL27 in bleomycin-induced mouse models showed that inhaled CL27c effectively reduced lung fibrosis by decreasing collagen deposition and downregulated key pro-fibrotic markers, including TGF-β1, CTGF, Collagen type I (Col1a1), and matrix metalloproteinase-2 (MMP2) (75).