"Data suggest that mature KLK9 (kallikrein 9) is a glycosylated chymotrypsin-like enzyme with strong preference for tyrosine over phenylalanine at P1 cleavage position; substrate specificity of KLK9 appears to extend to KLK10 and midkine; enzyme activity is enhanced by Mg2+ and Ca2+ but is reversibly attenuated by Zn2+; KLK9 is inhibited in vitro by many naturally occurring or synthetic protease inhibitors."xsd:string