ACTA1 and idiopathic pulmonary fibrosis: In contrast, in IPF lung clusterin staining was weak or undetectable in fibroblasts associated with fibrotic regions (Fig. 2A,C) and particularly in αSMA positive myofibroblasts in fibroblastic foci (Fig. 2A,B), whereas fibroblasts in morphologically normal areas of IPF-lung showed strong clusterin staining comparable to that of fibroblast-like cells in control lungs (Fig. 2D).