For the mucin locus signal (rs779167905 allele T), the allele associated with risk of chronic sputum production was also significantly associated with increased risk of asthma (OR 1.06; p=0.0027) and moderate-to-severe asthma (OR 1.13; p=6.3×10−7), increased FVC (β=0.0087; p=6×10−4) and decreased risk of IPF (OR 0.84; p=7.5×10−6) (figure 3 and supplementary table S6). Here, MUC5AC is linked to asthma.