GO curators for mouse genes have assigned the following annotations to the gene product of Cst3. (This text reflects annotations as of Wednesday, January 23, 2013.) Summary from NCBI RefSeq
[Summary is not available for the mouse gene. This summary is for the human ortholog.] 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 the most abundant extracellular inhibitor of cysteine proteases, which is found in high concentrations in biological fluids and is expressed in virtually all organs of the body. A mutation in this gene has been associated with amyloid angiopathy. Expression of this protein in vascular wall smooth muscle cells is severely reduced in both atherosclerotic and aneurysmal aortic lesions, establishing its role in vascular disease. [provided by RefSeq, Jul 2008]Summary text based on GO annotations supported by experimental evidence in other organisms
From comparative sequence analysis (see table for details), MGI curators have determined that the gene product of Cst3:
participates in the following biological processes: