Carriers of the risk MUC5B allele for IPF (rs35705950 TT or TC genotype) had lower prevalence of qualifying variants (84 [13·5%] of 622) compared with people carrying the protective GG genotype (60 [22·6%] of 266; p=1·03 × 10–3). The gene discussed is MUC5B; the disease is idiopathic pulmonary fibrosis.