ABCG2 and glioblastoma: Shown to be effective in sensitizing irinotecan and TMZ resistant tissues in human GBM xenografts without potentiating the myelotoxic effects.Also shown efficacy in sensitizing neuroblastoma or noradrenaline transporter expressing glioma cells to radiation exposure.Reported complete regression of tumor for more than 60 days when given in combination with TMZ.It is, however, found to be a substrate for ABC transporters and has poor BBB penetration in GBM murine xenografts