And even in a multi-center casecontrol study, there may be biomarker concentration differences. A 4 marker-panel, for example, exhibited concentration differences between biomarker discovery set and independent validation set. It has been accepted that there may be demographic and epidemiological differences, and sample processing protocols differences between hospitals, leading to different results. Thus, a model for estimating analytical and biological components of variation of markers is needed. Then, the careful evaluation of screening performances in appropriate sample cohorts would be required to further improve the specificity and sensitivity of the combined biomarkers in both retrospective and prospective clinical trials and lead to increased survival. Third, a multimarker bead-based system has several benefits for the immunoassay using clinical samples compared with the conventional enzyme-linked immunosorbent assay techniques and proteomic-based analyses. However, there are some difficulties inherent to the set up for multiplexing. A good pair of capture antibody and detection antibody RAD001 should be determined, and cross-reactivity among different antibodies for multiplexing should be avoided using application-specific antibody validation. Antibody cross-reactivity may produce a large background signal, thereby decreasing assay sensitivity. Theoretically, a factor that may limit the ability to multiplex. Several commercially available Luminex multiplex panels have been compared with conventional commercial ELISAs for measurement of biomarkers in human plasma that are associated with obesity and inflammation, showing that significantly improved and faster validation methods would be available for ovarian cancer research. In addition to adjusting cross reactivity, assay diluents, optimal temperatures, incubation times, concentrations of reagents, and analytical validation of assay performance must be configured during multiplex assay development. The present study showed the significant improvement of sensitivity for the diagnosis of ovarian cancer when using a combination of three serum biomarkers, including CA125, transthyretin, and apolipoprotein A1, using a multiplex liquid assay system. Further studies are going to be extended to a large number of ovarian cancer patients in early and late stages, as well as patients with benign ovarian diseases, in order to confirm the validity of the combination of these markers for the diagnosis at an early stage of ovarian cancer. PCA generally affects men over 65 years of age but remains indolent and asymptomatic in a majority of cases. The histopathological and molecular heterogeneity of the disease makes prediction of prognosis challenging. Although PSA is the most widely used serum marker for prostate cancer, it has no accepted cut-off point with high sensitivity and specificity and often leads to false positive results. Furthermore, there are currently no molecular markers that can be used to reliably predict which premalignant lesions will recur or develop into invasive PCA. A valid biomarker should have the following characteristics: accuracy; selectivity and specificity. Although PSA fulfills most of these criteria and is widely used, it is limited by its low values of specificity and selectivity. Because of the growing evidence for overtreatment of prostate cancer, it is important to identify and validate new prognostic markers that will predict clinically significant prostate cancer. Such markers will enable the targeted treatment of patients with aggressive tumors while avoiding unnecessar.