Predicted to enable serine-type endopeptidase inhibitor activity. Predicted to be located in extracellular space. Expressed in head neurons and pharynx. Human ortholog(s) of this gene implicated in severe acute respiratory syndrome. Is an ortholog of several human genes including PI3 (peptidase inhibitor 3); SLPI (secretory leukocyte peptidase inhibitor); and WFDC12 (WAP four-disulfide core domain 12).