Results from recent studies provided evidence that viruses can infect the alveolar epithelium and may be documented in lung tissues from patients using virus DNA detection and immunohistochemistry. A number of specific antibodies are currently available and should prompt to investigate the presence of the above cited viruses in the lung tissues from children with ILD. Surfactant disorders Surfactant disorders include mainly genetic surfactant protein disorders and pulmonary alveolar proteinosis