BIOSPECIMEN AND BIOMARKER CORE: PROJECT ABSTRACT The Biospecimen and Biomarker (BB) Core, Core B, will provide outstanding leadership and expertise in biospecimen sciences and molecular analyses needed in this P01 to investigate the evolution of two of the most common brain tumors, glioblastoma and meningioma. High-quality, well-annotated biospecimens and rigorous and standardized analysis of tumor tissue are essential for testing the hypotheses associated with the scientific Projects. The Core will acquire, annotate, distribute, track, and analyze brain tumor patient biospecimens from the operating room. This will include the acquisition and analysis of image-guided regional and multiple spatially distinct samples from patients with newly-diagnosed and recurrent meningioma and GBM. In addition, the Core will provide histopathologic and molecular analysis of both human tumors and human tumor xenografts. The overall goal of the Core is to improve the outcomes of patients with glioblastoma, IDH-wildtype, (GBM) and meningioma by working with the four research Projects and three other Cores to acquire high-quality, well- annotated biospecimens and apply routine and advanced analytic methods that describe tumor heterogeneity. Specific Aims of P01 Biospecimen and Biomarker Core: Aim 1. To provide the staff and expertise for the acquisition and optimal preservation of high-quality biospecimens, including whole tumor sampling, and their 3D spatial coordinates from the operating room. Aim 2. To provide standardized routine and advanced tissue handling/processing and analytical techniques, including multiplex immunoprofiling, multiplexed protein and RNA assays, and quantitative whole slide image analysis that will allow each Project to fulfill its goals. Aim 3. To provide biospecimen and neuropathology expertise to ensure optimal biospecimen quality and extraction of high-quality, quantitative data from biospecimens collected from the operating room and animal models. Aim 4. To provide consistent oversight of the Core activities that will ensure the stringent compliance with regulations governing informed consent and patient confidentiality, as well as management of the biospecimens and the information derived from the biospecimens. This will include maintaining a tissue inventory and database of associated molecular parameters that is linked to the Brain Tumor Center Database, integrating imaging, clinical, molecular, and pathology data. Impact: Well annotated clinical, imaging, histopathological and genomic data will be generated through close collaboration with the Projects, ITHM, and ACS to advance our understanding of tumor heterogeneity and to provide insights into novel therapeutic strategies for patients with glioblastoma and meningioma.