Armanios et al. observed 73 families with f-IPF, six of whom (8%) had shorter telomeres in peripheral blood leukocytes than those observed in their peers, and TERT/TERC heterozygous mutations encoding RNA ligands of the telomerase complex in an autosomal dominant inheritance pattern 43. The gene discussed is TERT; the disease is idiopathic pulmonary fibrosis.