Finally, alveolar macrophages predominate in desquamative interstitial pneumonitis (DIP), nonspecific interstitial pneumonia (NSIP), pneumoconiosis, unclassifiable ILD (U-ILD) and also in the pulmonary Langerhans cell histiocytosis (PLCH), although in the latter, an increase in CD1a positive Lanhergans cell is usually detected. This evidence concerns the gene CD1A and interstitial lung disease.