Surfactant Protein C (SP-C) is a small protein that plays a crucial role in the lungs. It is a component of pulmonary surfactant, a substance that reduces surface tension in the alveoli, the tiny air sacs where gas exchange occurs. By preventing the collapse of these sacs during exhalation, SP-C helps maintain proper lung function and facilitates breathing. SP-C is produced by alveolar type II cells, which are specialized cells in the lungs. Mutations in the gene responsible for SP-C can lead to respiratory diseases, such as surfactant dysfunction disorders. Understanding SP-C is essential for developing treatments for these conditions and improving lung health.