Enables cysteine-type peptidase activity. Involved in several processes, including glial cell apoptotic process; response to estradiol; and response to ischemia. Located in cytosol; mitochondrion; and nucleus. Used to study pre-malignant neoplasm. Biomarker of several diseases, including cerebrovascular disease (multiple); heart disease (multiple); kidney disease (multiple); neurodegenerative disease (multiple); and post-traumatic stress disorder. Human ortholog(s) of this gene implicated in several diseases, including Parkinson's disease; colorectal cancer; lung non-small cell carcinoma; pancreatic cancer; and type 2 diabetes mellitus. Orthologous to human CASP9 (caspase 9). [provided by Alliance of Genome Resources, Apr 2022]