The susceptibility genes associated with the pathogenesis of IPF are currently classified into four categories: (1) genes related to alveolar stability (such as SFTPC, SFTPA1, SFTPA2); (2) genes related to accelerated cellular senescence by disrupting telomerase function (such as TERT, TERC, DKC1, PARN, and RTEL1); (3) genes related to host defense (such as MUC5B and TOLLIP); and (4) genes related to impaired integrity of the epithelial barrier (such as DSK) [8,9]. The gene discussed is MUC5B; the disease is idiopathic pulmonary fibrosis.