The long-term objective of this proposal is to develop a simple, reliable, sensitive, and cost-effective technological platform that will allow the simultaneous and quantitative analysis of multiple antigens in human tumor samples derived from archived tissue specimens. Such a platform is urgently needed in the clinical laboratory setting to thoroughly characterize cancer. Multiplex analysis of molecular markers can augment and improve conventional methods for determining the primary anatomical site of tumor origin, predicting tumor behavior, and formulating effective therapy. SuperArray Inc.'s proprietary ID-Tag Protein Profiling technology is an antibody-based multiplex detection. Multiple ID tags are used to track multiple protein targets simultaneously. ID-tag signal can be further amplified to increase assay detection limit. Therefore, it is very promise to develop a simple clinical diagnostic tool that will be supersensitive and allow the simultaneous analysis of multiple antigens from archival material such as paraffin-embedded sections and alcohol-fixed cytology specimens. In this phase I proposal, SuperArray, Inc., will collaborate with Dr. Jian Yu Rao, Department of Pathology, University of California at Los Angeles, to evaluate the feasibility and application of the ID-Tag Protein Profiling Array technology for the molecular characterization of human cancers.