Enables serine-type endopeptidase inhibitor activity. Involved in defense response to Gram-negative bacterium; negative regulation of plasminogen activation; and regulation of angiogenesis. Acts upstream of or within several processes, including cellular response to transforming growth factor beta stimulus; placenta development; and regulation of angiogenesis. Located in extracellular space. Is expressed in several structures, including aorta; extraembryonic component; liver; oocyte; and placenta. Used to study Coronavirus infectious disease. Human ortholog(s) of this gene implicated in several diseases, including artery disease (multiple); autoimmune disease (multiple); diabetic retinopathy (multiple); liver disease (multiple); and lung disease (multiple). Orthologous to human SERPINE1 (serpin family E member 1). [provided by Alliance of Genome Resources, Apr 2022]