ABCA3, or ATP-binding cassette sub-family A member 3, is a protein encoded by the ABCA3 gene in humans. It plays a crucial role in the lungs, particularly in the production and secretion of pulmonary surfactant, a substance that reduces surface tension in the alveoli, helping to keep them open for efficient gas exchange. Mutations in the ABCA3 gene can lead to various lung diseases, including surfactant dysfunction disorders. These conditions can cause breathing difficulties and are often diagnosed in newborns. Understanding ABCA3 is essential for developing treatments for related respiratory issues.