Immunocytochemistry findings of collagen type I and HSP47 expression in A549 cells incubated for 48 h with various concentrations of TGF-β1. Collagen expression: 0 (a), 1 (b), 5 (c), and 10 ng/ml (d) of TGF-β1. HSP47 expression: 0 (e), 1 (f), 5 (g), and 10 ng/ml (h) of TGF-β1. Original magnification, x400. Positive rates of collagen type I (i) and HSP47 (j) immunostaining of A549 cells after incubation with TGF-β1 (0, 1, 5, 10 ng/ml) for 48 h. Positive rate of stained cells are significantly increased by TGF-β1 compared with control. Values are means ± SEM of 5 experiments.