Surfactant Protein-A (SP-A)

Surfactant Protein A (SP-A) is located in type II alveolar epithelial cells of lungs and plays an important role in maintaining alveolar surface tension. SP-A is one of the specific markers of lung epithelial cell type II, also highly expressed in bronchiolar carcinomas and lung adenocarcinomas. It is mainly used in combination with TTF-1 for the diagnosis of primary and metastatic lung cancer.