Lung histology with hematoxylin and eosin staining and Ashcroft score at 14 days. Wild-type mice demonstrates only mild fibrosis (A), whereas acatalasemic mice shows more severe fibrosis along with infiltration of inflammatory cells in the lungs (B). In fibrotic regions of the lungs, clusters of cuboidal bronchiolar-appearing epithelium were present adjacent to bronchioles ("bronchiolization") in each inset, a cluster of single-layered cells (grade I) in A and tubular structures of stratified cuboidal cells (grade II) in B. (C) Ashcroft score is higher in acatalasemic mice than in wild-type mice at 14 days after bleomycin administration. Scale bar = 100 μm. Scale bar in inset = 25 μm.