Predicted to enable cysteine-type endopeptidase inhibitor activity and protease binding activity. Acts upstream of or within adult locomotory behavior. Located in collagen-containing extracellular matrix. Is expressed in several structures, including alimentary system; genitourinary system; nervous system; respiratory system; and sensory organ. Used to study Unverricht-Lundborg syndrome. Human ortholog(s) of this gene implicated in Unverricht-Lundborg syndrome and progressive myoclonus epilepsy 1A. Orthologous to human CSTB (cystatin B). [provided by Alliance of Genome Resources, Apr 2022]