Also inhibits some cysteine proteases such as caspase, papain, bromelain or ficin. Fab fragments are generated by cleavage of IgG with papain instead of pepsin. Researchers in this case used cysteine proteases such as papain and poliovirus 3C protease. Cathepsin S is a lysosomal enzyme that belongs to the papain family of cysteine proteases. Specifically, it is an inhibitor of trypsin and papain. Several families of cysteine proteases use this triad set, for example TEV protease and papain. It is sensitive to trypsin but resistant to chymotrypsin, papain and pronase. Papain can be found in meat tenderizer and papaya. Also recommended is papain, an enzyme that breaks down protein. Some species, such as the papaya, bear edible fruit and produce papain. This purified papain may be supplied as powder or as liquid. Left untreated, papain activity will lead to complete lysis of the cells. Papain has been known to interfere with urine drug tests for cannabinoids. Meat tenderisers in powder form with papain as an active component are widely sold.