However, increased serum PRDX4 level was associated with an aggravation of pulmonary inflammatory changes, fibrosis, and poor prognosis in the murine model; therefore, elevated serum PRDX4 levels observed in patients with AE-IPF may originate from increased PRDX4 expression in the lungs. The gene discussed is PRDX4; the disease is idiopathic pulmonary fibrosis.