Genetic mutations to TERC, DKC1 (responsible for production of dyskerin that maintains telomeres), or poly(A) ribonuclease (PARN) can lead to reductions in TERC expression levels, and dysregulation of these genes are often observed in patients suffering from severe forms of dyskeratosis congenita (DC) or IPF [44,45,46,47]. The gene discussed is PARN; the disease is dyskeratosis congenita.