Fig. 2— Comparative immunohistochemistry for human airway myofibroblast (a, b, e, f, i and j) and smooth muscle (c, d, g, h, k and l) cultures, derived from an endobronchial biopsy and a lung resection specimen, respectively. Immunostaining was performed for α-smooth muscle actin (a and c), proline-4-hydroxylase clone 5B5 (b and d), vimentin (e and g), smooth muscle myosin (f and h) and pan cytokeratin (i and k). j and l) Immunoglobulin G1 as negative controls. The patterns shown are representative of three experiments. Scale bars = 100 μm.