Ovarian cancer is the second most common malignant gynecological cancer estimated number of newly diagnosed patients is about 42700 in the European Union, while this number is 1300 in Hungary and 811 in Serbia per year. Unfortunately, 70 percent of patients has been diagnosed in advanced stage the disease by presently used CA-125 biomarker, when the cancer is spread throughout the abdomen and causing low survival rates. Therefore identification of potential new biomarker such as PLs could improve our efforts to increase prevalence for early detection of ovarian cancer that is the most important issue for the patients. During this cross-border cooperation novel two dimensional liquid chromatographic mass spectrometric (2D-LC-MS) analytical method will be developed which will be applied in discovery of a new putative phospholipid biomarker of ovarian cancer from human plasma and it's comparing with the most using biomarkers for ovarian cancer CA 125 and HE4.Patients for this research will be selected from South Great Plain and Vojvodina regions. Patient's selection will be based on own evaluated statistical data of ovarian cancer epidemiological background in both regions. These statistical data will be benefit for these regions and will be the base of futher studies. Additional benefit of this project is that the analytical and clinical researchers will be able to think multidisciplinary, to share analytical, preclinical, clinical knowledges and to combine their efforts to understand and explain biochemical changes in the early stage of ovarian cancer. Results of the research would be a starting point of drug development against ovarian cancer. Cooperation between clinicians, bio- and analytical chemists will be useful as the problem will be analyzed from wide aspects which will increase benefits for scientists and the patients. The results will be published in scientific journals and will be also reported for public. Achievements: Ovarian cancer is the leading cause of cancer-related deaths and the 5th most common cancer among women in the world. Unfortunately, 70 percent of patients are diagnosed in the late advanced stage of the disease when the efficacy of the therapy and chances of long-term survival are lower. However, early stages ovarian cancer can usually be treated successfully with conventional therapies. So the partners’ aim was to identify a potential new biomarker which could help with the early detection of ovarian cancer. Nine Hungarian and Serbian researchers worked for 18 months to identify this potential biomarker, which could save many lives. They involved 130 patients from the South Great Plain and Vojvodina regions, held a total of ten conferences and meetings, developed an analytical model, optimised a preparation and created four publications.The additional benefit of this project was that analytical and clinical researchers were able to think in a multidisciplinary way, they exchanged analytical, preclinical and clinical knowledge and combined their efforts to understand and explain biochemical changes in the early stages of ovarian cancer.