Many of the same proteins that were identified by unsupervised hierarchical clustering (Fig. 2) and by linear regression analysis (Fig. 4; Additional file 1), were also significantly higher in the late stage ovarian cancer patients relative to the healthy women, e.g. MK, KLK6, hk11, CXCL13, FR-alpha, IL-6, and FADD. Here, KLK6 is linked to ovarian cancer.