Despite the many advances in cancer therapy, the survival of patients diagnosed with advanced and metastatic cancers remains essentially unchanged from the start of the “War on Cancer” declared by President Nixon.  Our laboratory focuses primarily on the biology of primary brain tumors, malignant gliomas and medulloblastomas.  These cancers, like most cancers, display a cellular heterogeneity that may contribute to the changes faced in our current ineffectual brain cancer therapies.  A subset of cancer cells may share some characteristics with normal stem cells and be responsible for maintenance of tumor growth.  We have recently shown that these cancer stem cells contribute to resistance to radiation therapy and promote the growth of new blood vessels to form the tumor, called angiogenesis.  Many new cancer therapies are directed against specific molecular targets active in cancer cells.  We are currently examining the cancer stem cells to better identify signal transduction pathways or novel drugs that can be used to kill the cancer stem cells.  We have also developed interests in the regulators of brain tumor invasion, which may also be driven by cancer stem cells.  Our research has additionally begun to extend towards the study of normal stem cells to understand how cancer stem cells and neural stem/progenitor cells function in parallel or different ways.  We hope that the new approaches in the study of a brain tumor cellular hierarchy may yield improved patient treatments.