(A) IHC evaluation on the SMAD7 expression in the lung sections from normal control and patients with SSc-ILD. SMAD7 staining of SSc-ILD lungs (right) reveals decreased number of Samd7-positive cells especially in the stromal region as compared with normal control (left) that showed a number of parenchymal cells and also macrophages are strongly stained. (B) Quantitation of SMAD7-positive (+) cells in the lung sections from controls and SSc-ILD per high-powered field. (C) Serum CHIT1 activity in the SSc-ILD patients with stable and progressive lung function. “Progressive” was defined in the patients with more than 10% of absolute drop of forced vital capacity (FVC). (D) Survival analysis based on the levels of chitinase activity (below and above median value of 53.54 nM/ml/h) in the patients with SSc-ILD. SSc-ILD subjects (n = 56) with values exceeding the median value of 53.54 (dotted line) demonstrate reduced progression-free survival as defined by absolute loss of %FVC within 2 years of enrollment. Scale bars, 30 μm, **P < 0.01, ***P < 0.001, Spearman’s rank test. n, number of individuals subjected to the evaluation.