We propose to facilitate analysis of nervous system tumors in this group effort by providing centralized mouse pathology services, taking advantage of local expertise in mouse perfusion and analysis of mouse nerve and brain tumors. This Core facility will use components of a highly successful core laboratory located within the Department of Pathology at Cincinnati Children's Hospital for paraffin embedding, plastic embedding for EM and electron microscope beam time. The pathology core will serve as an essential component for the research activities at Cincinnati Children's Hospital and will provide services to 3 investigators from Cincinnati Children's Hospital, University of Cincinnati Genomic research Institute (GRI),and University of Minnesota. The specific aims of this core are to 1) provide investigators assistance in tissue based approaches for nerve histology, immunohistochemistry, and electron microscopy; 2) provide pathologic support for non-perfused tissue such as tumors from xenografts, with support from human pathologists.