CSF2 and pulmonary alveolar proteinosis: Based on the established link between GM-CSF and PPARγ in patients with PAP and in GM-CSF−/− mice (38, 55, 64, 65), the link between anti-GM-CSF antibodies and mycobacterial infection (40), and the role of PPARγ in innate immunity to mycobacteria (66, –, 68), we considered whether the macrophage effector function of GM-CSF is associated with PPARγ expression.