In this respect, in the last decade, mRNA and protein expression of various members of the KLK family has been studied extensively in a variety of normal and diseased human tissues, including the ovary and ovarian cancer 5,9,23 In normal human ovary tissues, KLK expression at the mRNA level is highest for KLK6–8 and 10, whereas low to moderate expression was noted for KLK1, 9, 11, 13 and 14 with no expression for KLK2–5, 12, and 15. (Table 1, Figure 1). This evidence concerns the gene KLK2 and ovarian cancer.