DKC1 and idiopathic pulmonary fibrosis: Interestingly, it has been reported that telomeres in circulating blood cells are shortened in many sporadic as well as familial cases, despite the fact that there are no mutations in TERT, TERC or DKC1. 31 The correlation between the telomere length and the occurrence of IPF suggests the causative role of shortened telomeres in IPF.