PARN and rheumatoid arthritis: Indeed, the UIP pattern may be observed in various ARDs, including rheumatoid arthritis (RA), systemic sclerosis (SSc) and anti-synthetase disorders, but also in other ILDs, including fibrotic hypersensitivity pneumonia and asbestos exposure, sarcoidosis, familiar forms of pulmonary fibrosis (Hermansky–Pudlak syndrome, and genetic diseases involving surfactant proteins or telomerase complex (TERT, TERC, RTEL1, PARN, or DKC1 mutations) and drug toxicity [2].