Activating protein were described as an efficient panel of new biomarkers for detecting early stage epithelial ovarian cancer in women. Apolipoprotein A1 is the major protein component of high density lipoprotein in plasma. It was shown that Apolipoprotein A1 concentration in blood is reduced in different types of cancer. Apolipoprotein A1 has been identified as a potential biomarker of ovarian cancer, colorectal cancer, chronic obstructive pulmonary disease and pancreatic cancer. However, controversial observations were also reported including up-regulation of Apolipoprotein A1 in a variety of malignant tumors of ovarian, liver, breast. Recently, apolipoprotein A1 was shown to enhance the sensitivity of CA125 for detecting early stage epithelial ovarian cancer and suggested a promising therapeutic agent for the treatment of ovarian cancer. However, when applied individually, the markers studied here did not surpass CA125 in their sensitivities and specificities in the diagnosis of ovarian cancer. Combining individual markers has been attempted by other researchers as one strategy to enhance the overall ovarian cancer detection rate. Here, we applied the combination of the two serum markers with CA125, and compared the sensitivities and specificities between the threemarker panel and each marker alone. Results from ROC curve analysis show that combining three biomarkers had a much improved sensitivity over that of each biomarker alone. The threebiomarker panel classified early-stage cancers with 93.9% sensitivity and late-stage cancers with 96.5% sensitivity at 95% specificity. We also added hemoglobin, one of our serum biomarkers published recently, into the panel to confirm whether this combination gives the highest classification power. But, the four-biomarker panel did not improve the overall sensitivity and specificity for discriminating between ovarian cancer and healthy individuals as compared to the three-biomarker panel in the ROC curve. Thus, regardless of hemoglobin, the three-biomarker panel was sufficient for maximum separation between noncancer and stage I+II or all stages of disease. The sensitivity and specificity of this panel for stage I+II are comparable to results with a four-biomarker panel selected from 96 candidate antigens Selumetinib MEK inhibitor measured by immunoassays with multiplex techniques. Their panel of biomarkers correctly classified 67% of benign lesions as noncancer. Another study demonstrated the clinical utility of a CA125/HE4 combined test for the discrimination of benign and malignant ovarian masses with 76.4% sensitivity at 95% specificity. The high specificity and corresponding increases in sensitivity for the three-biomarker panel has merit in ovarian cancer screening trials. It was, however, reported that for the general population, the PPV of a 6-marker panel measured by a multiplex bead-based immunoassay system would be 6.5%, indicating that 14 out of 15 women with a positive test result would experience false-positive test results. There are several limitations that need to be addressed regarding the present study. First, a clearer description of population such as age and racial distribution, nutritional status, presence of peritoneal carcinomatosis and ascites, presence of infection disease, exclusion of autoimmune disease or another malignancies could be very important for the evaluation of biomarker levels. Second, natural biological variation of certain markers and individual biological variation over time should also be considered as the associated variability could induce a number of assay measurement error by false-positive results.