At the protein level, low to moderate amounts were found for KLK1, 5–8, and 10–14; KLK2–4, 9 and 15 proteins are not expressed (Table 1, Figure 1).23 Compared to normal ovarian tissues, concomitant up regulation of twelve (KLK3–11 and 13–15) of the fifteen KLKs at the mRNA and/or protein expression level is characteristic for ovarian cancer (Table 1, Figure 2).24–40 Regarding the clinical impact of some of the KLKs, expression of KLK4–7, 10 and 15 indicates poor prognosis; KLK8, 9, 11, 13 and 14 are markers of a favorable prognosis. Here, KLK2 is linked to ovarian cancer.