Furthermore, a number of preliminary analyses suggest that certain kallikreins including KLK3 (Yu et al, 1995; Yu et al, 1998; Foekens et al, 1999), KLK5 (Yousef et al, 2002b, 2003c; Diamandis et al, 2003), KLK7 (Talieri et al, 2004), KLK9 (Yousef et al, 2003a), KLK10 (Luo et al, 2002), KLK13 (Chang et al, 2002), KLK14 (Borgono et al, 2003), KLK15 (Yousef et al, 2002c) may possess clinical utility as diagnostic, prognostic or predictive breast cancer biomarkers. The gene discussed is KLK4; the disease is breast cancer.