Anti-fibrinogen-like 2 antibodies are used in the immunodetection of the protein encoded by the FGL2 gene. In humans, the canonical protein has a reported length of 439 amino acid residues and a mass of 50.2 kDa. It is known to be a secreted protein. It is notably expressed in cytotoxic T-cells. It is believed to play a role in physiologic lymphocyte functions at mucosal sites. Post-translational modifications have been described, including glycosylation. Other names for this target antigen include pT49, fibroleukin, fibrinogen-like protein 2, and T49.