Lastly, we observed an association between MUC5B and risk of RA (HR: 1.10, 1.04–1.17, p=0.0009), with a somewhat larger association in men (HR: 1.17, 1.05–1.30, p=0.005) than in women (HR: 1.08, 1.01–1.16, p=0.04). This evidence concerns the gene MUC5B and rheumatoid arthritis.