Napsin A

Napsin A is an aspartic protease that mainly exists in type II alveolar cells. It can catalyze the production and maturation of surfactant protein B, which participates in maintaining the normal morphology and function of the lungs. In clinical practice, Napsin A mainly served as a highly sensitive and specific diagnostic biomarker for lung adenocarcinoma. Its combination with TTF-1 has important guiding significance in the differential diagnosis between lung adenocarcinoma (+) and lung squamous cell carcinoma (-), lung primary adenocarcinoma and lung metastatic adenocarcinoma. The low expression result of Napsin A is closely related to tumor aggravation and poor prognosis. Meanwhile, some research has found that Napsin A is expressed in some renal tumors such as metanephric adenoma, papillary renal cell carcinoma, and renal clear cell carcinoma, which has research and diagnostic value. In addition, Napsin A is expected to become a new diagnostic indicator for thyroid cancer and clear cell carcinoma of the female reproductive system.