MUC5B and idiopathic pulmonary fibrosis: In 2011, Seibold and colleagues, using a genome-wide linkage analysis, demonstrated that the minor allele (T) of a single nucleotide polymorphism (SNP) located 3 kb upstream of the MUC5B gene transcription start site on 11p15 (rs35705950) was present in 38% of subjects with sporadic IPF and in 34% of subjects with familial interstitial pneumonia [3].