Plerixafor in combination with bevacizumab is a drug combination that may stop cancer cells from growing abnormally. Bevacizumab, also known as Avastin, is FDA approved for use in patients with recurrent glioblastoma and has been studied extensively in other types of solid tumors. Plerixafor, also known as Mozobil, is FDA approved for use in patients with non-Hodgkin's lymphoma and multiple myeloma and has been used in treatment for other cancers. Information from experiments in laboratories suggests that the combination of plerixafor and bevacizumab may help prevent the growth of gliomas.