MUC16 and idiopathic pulmonary fibrosis: Immunohistochemical stainings of MUC16 in lung tissue from IPF patients showed MUC16+ staining in aberrant, hyperplastic alveolar epithelial cells (Figure 1C, arrows) and fibroblasts (Figure 1C, arrowheads) in IPF sections, and there was no or only rare MUC16 staining in lung sections from healthy subject specimens (Figure 1C).