Neutrophil elastase is an alias for the gene, Elastase, neutrophil expressed, in humans. Other names include: Neutrophil elastase; Bone marrow serine protease; Elastase-2; Human leukocyte elastase; HLE; Medullasin; PMN elastase; Neutrophil elastase ; leukocyte elastase; ELA2; HNE; NE; PMN-E. The encoded protein is an enzyme with an amino acid length of 267 and a mass of 28.5 kDa. Other isoforms may exist. Neutrophil elastase is a member of the Peptidase S1 family, Elastase subfamily. This gene shares homology with other species, including: Frog, Mouse.