MUC5B and pulmonary fibrosis: Despite the fact that the etiology of IPF is largely unknown, in some patients, abnormalities in genes such as surfactant protein A2 (SFTPA2), surfactant protein C (SFTPC), ELMO/CED-12 domain containing 2 (ELMOD2), mucin 5b (MUC5B), and two telomerase genes (hTERT and hTR) are considered as risk factors for pulmonary fibrosis (Khalil et al., 2001; Hodgson et al., 2006; Seibold et al., 2011; Armanios, 2012).