SUMMARY The project is aimed at the development of a new highly sensitive multi-tumor type imaging procedure. The imaging is based on a marker of the tumor blood vessels, the Follicle Stimulating Hormone Receptor (FSHR), which was shown by us to be present in all major cancer types and at all stages, advanced and incipient. The first Aim is to assemble the imaging agents and to test them in cell cultures. Anti-FSHR antibodies will be labeled with imaging agents, tested for binding to cells in culture that produce FSHR and will be optimized by selecting the best antibodies. The second Aim is to test the performance of the imaging agents in mice. The imaging agents will be delivered by intravenous injection in mice that carry tumors formed by implanting human tumor cells and the tumors will be imaged. A tumor cell line that generate metastatic lesions in mice will be used to determine the smallest tumor size that can be detected. Tumors will be analyzed in parallel by immunohistochemistry in tissue sections, in order to determine the yield and sensitivity of detection by imaging. The procedure can contribute to a national priority in cancer research – to reduce substantially cancer mortality by early detection of asymptomatic tumors. Early detection increases substantially the chance of successful therapy, and significantly reduces the overall cost of cancer treatment. The method could be initially tested for periodic screening of patients who are at high risk of developing cancer.