Aggressive therapies – including surgery, radiation and high-dose chemotherapy – have improved outcomes for medulloblastoma patients, but many patients still die of their disease, and survivors suffer severe long-term side effects from therapy. To develop safer and more effective treatments, we need to understand the genes and pathways that are important for tumorigenesis. But for many forms of medulloblastoma, the oncogenic drivers are still unknown. A major focus of our research is to identify these drivers and use them to create robust animal models of the disease. Sequencing studies have identified genes that are altered in human medulloblastoma, and we are using functional assays to determine which of these genes can promote tumor growth in vivo. We have also established a large bank of patient-derived xenograft models that we use to perturb candidate genes and test their roles in tumorigenesis. In addition to identifying new drivers of medulloblastoma, these studies generate models that can be used to test novel approaches to therapy.