Purity: > 95% by SDS - PAGE Format: Liquid. In 20mM Tris-HCl buffer (pH 8.0) containing 2mM DTT, 10% glycerol, 100mM NaCl. CST1 (Cystatin-SN) is a member of the type 2 salivary cystatin family found in a variety of fluids and secretions, including plasma, tears, and saliva. 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. CST1 was upregulated in cancerous lesions of gastric cancer tissues compared to noncancerous regions and clinicopathological analysis showed a significant correlation between high expression of CST1. Recombinant human CST1 protein, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography techniques.