My research focuses on medulloblastoma, a highly aggressive form of brain cancer in children. In many cancers, including medulloblastoma, patients succumb not to the primary tumor, but to recurrent disease that comes back after initial treatment. I will be using techniques in genome sequencing to compare differences in genetic alterations in tumors from medulloblastoma patients prior to treatment and after treatment relapse. Already, I have collected 50 "newly diagnosed" and "relapsed" tumor pairs from medulloblastoma patients enrolled in clinical trials at St. Jude Children's Research Hospital. I will compare the "before treatment" with "after treatment"tumor samples to detect differences in gene expression, gene mutations, and also gene fusions, deletions, and duplications. Further, I will study the genetic alterations discovered through these analyses to generate new mouse models of medulloblastoma—work that will ultimately provide additional direction for treating children with this form of recurrent brain cancer.