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. This gene encodes a glycosylated cysteine protease inhibitor with a putative role in immune regulation through inhibition of a unique target in the hematopoietic system. Expression of the protein has been observed in various human cancer cell lines established from malignant tumors.[7]
Saitoh E, Isemura S, Sanada K, etal. (1989). "Cystatin superfamily. Evidence that family II cystatin genes are evolutionarily related to family III cystatin genes". Biol. Chem. Hoppe-Seyler. 369 Suppl: 191–7. PMID3202964.
Thiesse M, Millar SJ, Dickinson DP (1994). "The human type 2 cystatin gene family consists of eight to nine members, with at least seven genes clustered at a single locus on human chromosome 20". DNA Cell Biol. 13 (2): 97–116. doi:10.1089/dna.1994.13.97. PMID8179826.
Morita M, Yoshiuchi N, Arakawa H, Nishimura S (1999). "CMAP: a novel cystatin-like gene involved in liver metastasis". Cancer Res. 59 (1): 151–8. PMID9892200.
Morita M, Hara Y, Tamai Y, etal. (2001). "Genomic construct and mapping of the gene for CMAP (leukocystatin/cystatin F, CST7) and identification of a proximal novel gene, BSCv (C20orf3)". Genomics. 67 (1): 87–91. doi:10.1006/geno.2000.6237. PMID10945474.
Nathanson CM, Wassélius J, Wallin H, Abrahamson M (2003). "Regulated expression and intracellular localization of cystatin F in human U937 cells". Eur. J. Biochem. 269 (22): 5502–11. doi:10.1046/j.1432-1033.2002.03252.x. PMID12423348.
Cappello F, Gatti E, Camossetto V, etal. (2004). "Cystatin F is secreted, but artificial modification of its C-terminus can induce its endocytic targeting". Exp. Cell Res. 297 (2): 607–18. doi:10.1016/j.yexcr.2004.03.048. PMID15212960.
