SERPINA1 (Serpin Family A Member 1): SERPINA1 is a marker that indicates the activity of a crucial protease inhibitor in the body, also known as alpha-1-antitrypsin. Mainly produced in the liver, it plays an important role in safeguarding the lungs against neutrophil elastase. A deficiency in SERPINA1 can cause alpha-1-antitrypsin deficiency, a genetic disorder linked to lung diseases like emphysema and COPD, as well as liver conditions. It is vital for maintaining proteolytic activity balance in lung tissues.