Furthermore, since its activity is also regulated by proteolytic cleavage of its N-terminal peptide by, supposedly, cathepsin V, the latter may control the inhibitory activity of cystatin F and, hence, the rate of inhibition of pro-granzyme convertases cathepsins C and H. Owing to the specific roles of cathepsins C, H, and V and cystatin F in regulating cell cytotoxicity, they are potential therapeutic targets for improving cell therapy or impairing cytotoxicity in immune disorders. The gene discussed is CTSV; the disease is immune system disorder.