Predicted to enable serine-type endopeptidase inhibitor activity. Predicted to be involved in negative regulation of endopeptidase activity. Predicted to act upstream of or within negative regulation of peptidase activity. Predicted to be located in extracellular region. Predicted to be active in extracellular space. Is expressed in brain. Orthologous to human SERPINA9 (serpin family A member 9). [provided by Alliance of Genome Resources, Apr 2022]