 Neutrophil elastase is closely related to other cytotoxic immune serine proteases, such as the granzymes and cathepsin G. It is more distantly related to the digestive CELA1.The neutrophil form of elastase () is 218 amino acids long, with two asparagine-linked carbohydrate chains (see "glycosylation").It is present in azurophil granules in the neutrophil cytoplasm.