SERPINB1 (Serpin Family B Member 1): SERPINB1 is a protein belonging to the serpin (serine protease inhibitor) family. It plays a crucial role in regulating proteolytic pathways involved in inflammation and immune responses. SERPINB1 primarily inhibits neutrophil elastase and cathepsin G, enzymes released by neutrophils during inflammation, helping to prevent excessive tissue damage. Its protective function in maintaining lung tissue integrity is particularly important in conditions like cystic fibrosis and chronic obstructive pulmonary disease (COPD), where reduced or impaired SERPINB1 activity can lead to increased tissue degradation and disease progression.