Western blot analysis of Lane 1: Human cell line RT-4 Lane 2: Human cell line U-251MG sp Lane 3: Human cell line A-431 Lane 4: Human liver tissue Lane 5: Human tonsil tissue with CSTA polyclonal antibody (Cat # PAB29355) at 1:250-1:500 dilution.
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 kininogens. This gene encodes a stefin that functions as a cysteine protease inhibitor, forming tight complexes with papain and the cathepsins B, H, and L. The protein is one of the precursor proteins of cornified cell envelope in keratinocytes and plays a role in epidermal development and maintenance. Stefins have been proposed as prognostic and diagnostic tools for cancer. [provided by RefSeq