DKC1 and idiopathic interstitial pneumonia: Short telomeres and reduced keratinoid-associated undesirable protein expression are found in families with f-IPF 102; however, no mutations in TERT, TERC, DKC1, or other genes known to induce DC were detected 103, suggesting that the abnormal regulation of the telomerase complex is another mechanism of telomere shortening in patients with PF.