Specifically, it was reported that MUC5B rs35705950 T-carrier status was associated with increased expression of MUC5B glycoprotein in both distal airways and honeycomb cysts in IPF lungs [15,16] Interestingly, IPF patients carrying the minor T allele, either in homozygous or heterozygous form, appeared to have a better outcome, compared to IPF patients who did not carry the T allele, although the mechanisms underlying this association remain to be elucidated [8,17]. This evidence concerns the gene MUC5B and idiopathic pulmonary fibrosis.