MUC5B and fibrosis: Genome-wide association studies have shown that the presence of a common polymorphism in the promoter region of MUC5B (rs35705950) is associated with the development of familial ILDs and IPF, and Scholand et al. demonstrated an association between expression of the mutant rs35705950 allele of MUC5B and cough severity, perhaps suggesting a direct link between the development of fibrosis and cough [6,7].