Enables cysteine-type peptidase activity. Involved in bone resorption; metanephros development; and regulation of sensory perception of pain. Located in cell surface. Biomarker of intracranial aneurysm. Human ortholog(s) of this gene implicated in neuropathy. Orthologous to human CTSS (cathepsin S). [provided by Alliance of Genome Resources, Apr 2022]