Project Summary The acquisition, pathologic analysis and molecular characterization of human and mouse model gastrointestinal (GI) samples is an integral requirement for all portions of this SPORE. This Core will continue to provide SPORE investigators multiple pathology services to support Research Projects and future Career Enhancement Program (CEP) and Developmental Projects (DP) awardees. We will work in close collaboration with investigators to achieve three crucial purposes: i) to provide tissue specimens and pathology expertise to evaluate human and mouse models of GI neoplasms; ii) to provide molecular pathologic expertise in state-of-the-art molecular evaluation of tissue specimens; and iii) to evaluate and implement new tissue and cellular imaging and analysis technologies that will benefit these research goals in the future. Centralization of Core activities builds upon established infrastructure and expertise of these investigators, and complements but does not replicate existing infrastructure in our Cancer Center and provides a valuable component to the analysis of biological resources developed and utilized by SPORE investigators. To bring pathology based scientific support to all SPORE projects, this Core proposes the following specific aims: Specific Aim 1: To provide human biospecimen procurement and distribution. Specific Aim 2: Generation of models for pre-clinical trials Specific Aim 3: Pathologic characterization of human and mouse GI tumors using molecular pathology tools and emerging new technologies