CST9L: Proteins and Enzymes

The cystatin superfamily encompasses proteins that contain multiple cystatin-like sequences. Some of the members areactive cysteine protease inhibitors, while others have lost or perhaps never acquired this inhibitory activity. Thereare three inhibitory families in the superfamily, including the type 1 cystatins (stefins), type 2 cystatins and thekininogens. The type 2 cystatin proteins are a class of cysteine proteinase inhibitors found in a variety of humanfluids and secretions. The cystatin locus on chromosome 20 contains the majority of the type 2 cystatin genes andpseudogenes. This gene is located in the cystatin locus and encodes a protein similar to mouse cystatin 9. Based onits testis-specific expression, it is likely to have a role in tissue reorganization during early testis development.(provided by RefSeq)