High titers of neutralizing auto-Abs against granulocyte-macrophage colony-stimulating factor (GM-CSF) were first described in adult patients with idiopathic pulmonary alveolar proteinosis (PAP), a severe lung disease characterized by the accumulation of surfactants in the alveoli, progressive respiratory failure, and an increased risk of secondary infections [11]. The gene discussed is CSF2; the disease is respiratory failure.