Alpha-1 antitrypsin (AAT) is a protein produced by the liver that helps protect the lungs and other organs from damage caused by enzymes, particularly neutrophil elastase. This enzyme can break down tissues, and AAT acts as a shield to prevent excessive tissue damage, especially in the lungs. A deficiency in AAT can lead to various health issues, including lung diseases like chronic obstructive pulmonary disease (COPD) and liver problems. Genetic factors primarily cause this deficiency, and individuals may require treatments such as AAT augmentation therapy to manage their condition and protect their organs.