Surfactant Protein A (SP-A) is a lung-specific protein that plays a crucial role in the innate immune response and maintenance of lung surfactant homeostasis. It is a member of the collectin family of proteins, which are involved in the recognition and clearance of pathogens, allergens, and cell debris in the lungs. Research on SP-A has focused on its role in host defense against respiratory infections, regulation of inflammation in the lungs, and its potential as a biomarker for lung diseases such as acute respiratory distress syndrome and chronic obstructive pulmonary disease. Studies have also investigated the therapeutic potential of SP-A in treating lung disorders and improving lung function. Overall, research on surfactant protein A aims to improve our understanding of lung function, host defense mechanisms, and the development of new interventions for respiratory diseases.