In this study of IPF patients, stratified by MUC5B rs35705950 genotype, we did not observe any associations between MUC5B genotype and HRCT features of disease at baseline; conversely, after 12 months of antifibrotic treatment, the alveolar score increased significantly in the GG, but not in the TT/TG, genotype group, suggesting that GG genotype may increase the risk of radiological progression. Here, MUC5B is linked to idiopathic pulmonary fibrosis.