A major drawback in translational brain cancer research has been the lack of suitable animal models. Syngeneic-or xenograft tumors based on glioblastoma cell lines cultured as monolayers grow as circumscribed and highly angiogenic lesions in vivo [2] , lacking the invasive tumor cells, which represent an important feature of human glioblastoma. The invasive cells migrate away from the initial tumor mass and can cause recurrent tumors in different regions of the brain. Thus, these cells represent a major therapeutic target.