KLK4 and ovarian cancer: Four recent studies verified the overexpression of several kallikreins in ovarian cancer tissues (Yousef et al, 2003), in disseminated ovarian cancer cells isolated from ascites fluid of ovarian cancer patients (Oikonomopoulou et al, 2006b) and in ovarian cancer effusions (Shaw and Diamandis, 2007; Shih et al, 2007).