Pulmonary fibrosis showed increased expression of serine/threonine-protein kinase PLK2 (Q9NYY3) and NEDD4-binding protein 2 (Q86UW6), while alveolar infiltrates exhibited reduced expression of protein WWC3 (Q9ULE0), Rho-associated protein kinase 1 (Q13464), and apolipoprotein A-IV (P06727). Here, APOA4 is linked to pulmonary fibrosis.