NAF1 and idiopathic pulmonary fibrosis: Mutations in the genes involved in maintaining telomere length including telomerase reverse transcriptase (TERT), telomerase RNA component (TERC), (Fe-S) cluster containing regulator of telomere elongation helicase (RTEL1), poly-A specific ribonuclease (PARN), nuclear assembly factor 1 ribonucleoprotein (NAF1), TERF1 interacting nuclear factor2 (TINF2) and dyskerin (DKC1) have been discovered in approximately 25–30% of the familial IPF [37–42].