The SNP, rs35705950, was found to be a gain-of-function variant associated with increased expression of MUC5B. Heterozygous (GT) and homozygous (TT) individuals had an odds ratio for developing disease of 6.8 and 20.8 for FIP, and 9.0 and 21.8 for IPF, respectively, supporting the strength of the SNP’s association with development of both IPF and FIP (41). Here, MUC5B is linked to idiopathic pulmonary fibrosis.