ABSTRACT An integrated approach to Neuropathology is a central element of all studies detailed in the four projects. Focusing neuropathological aspects of this Program in a core facility allows closer coordination of the efforts of the Program?s investigators and provides an interface between the Program and key laboratories: Anatomic Pathology, Clinical / Research Neuropathology, and the VHC. Aside from the obvious benefits that a Neuropathology Core can provide in terms of concerted experimental design / planning and that come with a centralized and uniform approach to the processing and assaying of tissues, a Core can facilitate adherence to regulatory issues relating to the accessioning and processing of human and animal tissues for research, can produce financial benefits through efficient use of manpower and reagents, and can simplify and secure data recording and presentation. Core C pathologists are strategically placed to take advantage of the material they will review, comparing morphological and immunophenotypic variation in human and mouse CNS tumors in the context of a wealth of genetic data generated over the Program?s last budget cycle [2-4, 27-33]. The two Core C pathologists have an interest in the analysis of CNS tumors and proven expertise in this area, as reflected by their publications (see later in this section and biosketches). Together with the other project leaders, our Program team has the potential to capitalize on their findings by producing novel enhancements to the molecular classification of medulloblastomas and pediatric high-grade gliomas and potentially to lay the foundations for an integrated pathological and molecular approach to the diagnosis of pediatric CNS tumors, utilizing a combination of detailed histopathological evaluation and novel molecular markers to classify tumors for the purpose of therapeutic stratification or as suitable for novel targeted therapies.