Anti-MBL associated serine protease 1 antibodies are used for the immunodetection of the protein encoded by the MASP1 gene. In humans, the canonical protein has a reported length of 699 amino acid residues and a mass of 79.2 kDa. It is known to be a secreted protein. Alternative splicing is reported to yield 4 different isoforms for this protein. A member of the Peptidase S1 protein family, it is reported to function in the lectin pathway of complement, which performs a key role in innate immunity by recognizing pathogens through patterns of sugar moieties and neutralizing them. Post-translational modifications have been described, including N-glycosylation and protein cleavage. The gene encoding this protein is implicated in 3MC syndrome. Other names for this target antigen include CRARF, CRARF1, MAP-1, MAP1, MASP, MASP-3, MASP3, and 3MC1. Gene orthologs have been identified in the mouse, rat, bovine, frog, zebrafish, chimpanzee and chicken species.