The function of CAPNS2 (calpain small subunit 2, Ensembl gene identifier ENSG00000256812) is as follows. Calcium-regulated non-lysosomal thiol-protease which catalyzes limited proteolysis of substrates involved in cytoskeletal remodeling and signal transduction. This small subunit may act as a tissue-specific chaperone of the large subunit, possibly by helping it fold into its correct conformation for activity.