Figure 2. Disordered homeostasis of plasma TGF-β1 and its receptors in patients with COPD.

Standardized sandwich ELISA of plasma from healthy controls (HC, n = 27), healthy smokers (HS, n = 24) and COPD patients (n = 29) were performed to assess the levels of (a) TGF-β1, (b) TGF-β1 RI, (c) TGF-β1 RII, and (d) BAMBI. The data are represented as the mean ± SEM; a value of P < 0.05 was considered statistically significant.