Anti-MBL associated serine protease 2 antibodies are used for the immunodetection of the protein encoded by the MASP2 gene. In humans, the canonical protein has a reported length of 686 amino acid residues and a mass of 75.7 kDa. It is known to be a secreted protein. Alternative splicing is reported to yield 2 different isoforms for this protein. It is notably expressed in plasma. A member of the Peptidase S1 protein family, it is reported to be a serum protease that plays an important role in the activation of the complement system via mannose-binding lectin. Post-translational modifications have been described, including protein cleavage. The gene encoding this protein is implicated in MASP2 deficiency. Other names for this target antigen include MAP19, MASP1P1, sMAP, mannan-binding lectin serine protease 2, MBL-associated plasma protein of 19 kD, and MAP-2. Gene orthologs have been identified in the mouse, rat, bovine, frog, zebrafish, chimpanzee and chicken species.