These features include patchy pulmonary fibrosis with honeycombing-like cysts, fibroblast foci-like structures, bronchiolization of peripheral airways, altered pulmonary expression of Muc5b and other IPF modifier genes, a commonly altered proteomic signature, and death due to respiratory failure (Fig. 2, Fig. 3, and Fig. 7). Here, MUC5B is linked to pulmonary fibrosis.