产品描述：

background: The cystatin superfamily encompasses proteins that contain multiple cystatin-like sequences. Some of the

members are active cysteine protease inhibitors, while others have lost or perhaps never acquired this

inhibitory activity. There are three inhibitory families in the superfamily, including the type 1 cystatins (stefins),

type 2 cystatins and the kininogens. The type 2 cystatin proteins are a class of cysteine proteinase inhibitors

found in a variety of human fluids and secretions, where they appear to provide protective functions. The

cystatin locus on chromosome 20 contains the majority of the type 2 cystatin genes and pseudogenes. This

gene is located in the cystatin locus and encodes a cysteine proteinase inhibitor found in saliva, tears, urine,

and seminal fluid. [provided by RefSeq, Jul 2008]