MUC5B and idiopathic pulmonary fibrosis: Idiopathic pulmonary fibrosis is a progressive interstitial lung disease arising around the distal airway/alveoli that involves epithelial cell death, inflammation and fibrosis, with few treatment options and a high mortality rate.68 Although the aetiology is unclear, there are several strong genetic links to predisposition to IPF, including rare alleles in surfactant (SFTPC, SFTPA2) and telomerase pathway (TERT, TERC, PARN and RTEL) genes, and more common alleles of MUC5B strongly associated with a less aggressive form of IPF (reviewed by Evans et al. 68).