Neuroblastoma accounts for a disproportionate amount of childhood cancer deaths. Immunotherapy approaches hold great promise for the treatment and potential cure of childhood and adult malignancies. However, the optimal cell surface proteins to target in NB at diagnosis and relapse remain unknown. With the support of the W.W. Smith Charitable Trust and an Innovation Award from Alex’s Lemonade Stand Foundation (ALSF), we are comprehensively profiling the cell surface landscape (surfaceome) of neuroblastoma at both diagnosis and relapse. To do this, we are utilizing a combination of human-derived neuroblastoma cell lines, patient derived xenograft models, and frozen tumor samples from patients. Knowledge of this repertoire of proteins (surfaceome), in combination with extensive normal tissue expression data, will greatly facilitate the identification of new and/or combinatorial immunotherapeutic targets. Our lab is further validating cell surface expression and demonstrating functional relevance of prioritized cell surface candidates. We expect to deliver (1) the definable landscape of cell surface protein expression (surfaceome) in neuroblastoma, including how these proteins evolve under the selective pressure of chemotherapy, and (2) a high confidence set of validated cell surface proteins to undergo subsequent antibody-based or Chimeric Antigen Receptor (CAR) T-Cell development. Recently, through a collaborative U54 within the new Pediatric Immunotherapy Discovery and Development Network (PI-DDN) our approach is being applied to explore the surfaceome of additional high-risk childhood cancers.