PAP can be caused also by mutations in surfactant protein B (SFTP3-gene), surfactant protein C, ATP-binding cassette 3, or NK2 homeobox, resulting in a dysfunctional surfactant release from type II epithelial cells and abnormal clearance from the alveoli, leading to the accumulation of lipoproteinaceous deposits in the alveoli [7,8]. The gene discussed is SFTPB; the disease is pulmonary alveolar proteinosis.