Kazutoshi Cho, MD is Clinical Professor of Hokkaido University Hospital and General Manager of Maternity and Perinatal Care Center of Hokkaido University Hospital. He completed fellowships in pediatrics in Hokkaido Prefecture, and started study on pulmonary surfactant at Iwate Medical University in 1990. His mentor in this field was Professor Tetsuro Fujiwara who established surfactant replacement therapy for respiratory distress syndrome in premature infants. Dr. Cho returned to Hokkaido in 1994 and met the siblings with congenital pulmonary alveolar proteinsis (CPAP). There were three affected individuals in four siblings. After many years of efforts, he decided OAS1 is the responsible gene for a novel type of primary immune deficiency complicated with CPAP, hypogammagloburinemia and some other common features. Dr. Cho is a neonatologist, a pulmonologist and also a genetic scientist. He is now performing clinical supports and advices about genetic interstitial lung diseases for neonatologists and pediatricians in Japan.