Cystatin-9 (CST9)

Cystatin-9 (CST9) is a secreted human protein and a member of the type 2 cystatin superfamily, which comprises inhibitors of cysteine proteases such as cathepsins[1][2][3][7]. While some cystatins directly inhibit cysteine protease activity, the inhibitory function of Cystatin-9 itself is not fully established[1]. It is thought to be involved in hematopoietic differentiation and the modulation of inflammation, and may have immunomodulatory and antimicrobial activity, such as activity against Francisella tularensis[1][7][8]. Cystatin-9 is mainly expressed in human fluids and secretions, and related research suggests possible roles in testis development and in the immune response. Diseases associated with CST9 include pneumonic tularemia; however, specific therapeutic or drug targeting information is not established[1][5][7].

Other names

Cystatin-9CST9CLMCTES7Acystatin-like moleculetestatin