As a proof of this principle, in a recent study, a panel of kallikreins (KLKs 4, 5, 6, 7, 8, 10, 11, 13 and 14) was able to confidently discriminate cancerous from benign effusions, with an area under the ROC curve of 0.99, and ovarian cancer from other cancer groups with an AUC of 0.96 (Shih et al, 2007). Here, KLK4 is linked to cancer.