Statin therapy was associated with improvement in lung disease in autoimmune PAP patients, reduced cholesterol levels in alveolar macrophages from autoimmune PAP patients ex vivo, increased cholesterol efflux from Csf2rb−/− macrophages ex vivo, and ameliorated lung disease in Csf2rb−/− mice in vivo. This evidence concerns the gene CSF2RB and autoimmune pulmonary alveolar proteinosis.