Validation of potential target (AREB6, PAX8, ELF3) using western blots (A) and expression of E2F5 in serum from normal, benign and, malignant patient samples (B). (A) Target validation using western blots of AREB6, PAX8, ELF3, in serum of healthy volunteers (N) (n = 2), patients with benign ovarian cysts (B1, B2) (n = 2), and patients with late- (L1, L2) (n = 2) and early-stage (E1-E3) (n = 3) serous adenocarcinoma. AREB6 was overexpressed in late stage disease, but was not discriminatory for early cancer. PAX8 and ELF3 were equally expressed in all serum samples. (B) Expression of E2F5 in serum from normal (n = 56), benign (n = 40) and, malignant (n = 48) serum obtained from patients with cancer of the ovary.