Pediatric brain tumors are now the most common cause of mortality from disease in childhood. Molecular characteristics of pediatric high- and low-grade gliomas (PHGG and PLGG), the most common tumor category overall, are crucial to treatment and outcomes, but the impact of these characteristics and of the variety of cell populations in these tumors is poorly understood. We performed single-cell RNA-sequencing on viably banked single cell samples of high- and low- grade glial tumors from children treated at Children’s Hospital Colorado. These samples are part of ongoing single-cell pediatric brain tumor banking that our group initiated a decade ago. The maturity of this resource, collected over a decade, provides us with the opportunity to perform well-powered outcome association studies. Samples are collected during routine surgery and immediately disaggregated to isolate single cells. These are then viably frozen in DMSO and banked for later use. We have tumors that cover the variety of subtypes in each of these diseases, as well as comprehensive clinical information on these cases, which will allow us to correlate molecular subtypes and research findings with these clinical measures. Here, we perform single-cell RNA-sequencing on 23 samples from patients with PHGG. In PHGG, we aim to understand the extent to which pediatric HGG stem like cells may differentiate into other cell types found in HGG tumors, or whether the non-stemlike cells may be derived from host tissue; whether gene expression is altered in host cells as the result of interactions with tumor stem cells; and the extent to which specific gene expression patterns among tumor cell subpopulations correlate with outcome measures such as mortality or event-free survival. These studies will significantly advance our understanding of disease biology and provide the detailed molecular and functional insights needed to identify new therapeutic targets for these biologically and clinically heterogeneous tumors.