RecruitingClinical trialPost Mortem Tissue Donation of Pediatric Tumor Tissues and CellsThe objective of this study is to utilize all donated pediatric tumor tissues and cells obtained from autopsy to prospectively develop novel patient derived orthotopic xenograft (PDOX) mouse models as well as in vitro cell culture model systems for pediatric cancers, and also provide tissue samples to other researchers and organizations (eg, CBTN, DIPG Registry, COG).