is a Professor of Neurosurgery at UCSF and holds the Karen Osney Brownstein Endowed Chair in Neuro-oncology. Dr. Costello is the Basic Science PI of the UCSF Brain Tumor SPORE, Director of the NIH supported Training Program in Translational Brain Tumor Research at UCSF and served as the Director of the UCSF-based NIH Roadmap Epigenome Mapping Center. He has substantial experience in teaching, mentoring, and scientific leadership. Examples of his activities include serving as mentor/co-mentor for undergraduate and medical student trainees, trainees at the PhD and postdoc level funded through F31, F32, and F99/K00 from NIH, medical residents on the Holman Pathway, NIH R25, and junior faculty who have received K08, K23 and R01 awards. The Costello laboratory is composed of cell, molecular and computational biologists working alongside clinician-scientists from Neurosurgery, Neuropathology, and Radiation Oncology. Our goal is to understand the full evolutionary history of human brain tumors, from the first mutation through cellular immortality, clonal selection and tumor recurrence. Current projects incorporate MRI guided tumor biopsies and treatment data with longitudinal genomics to allow the reconstruction of tumor evolution in the context of the human tumor in vivo. We recently discovered the multimeric factor, GABP, which is recruited by the mutation to activate TERT and immortalize brain cells, allowing them to maintain telomeres, proliferate indefinitely and evolve into tumors. We are pursuing studies of the role of GABP in tumor immortality and approaches to therapeutically target it to reverse immortality.