ABCC1 and glioblastoma: For instance, the ABCC1 (ATP-binding cassette transporter C1) transporter also known as MRP1 (Multi Drug Resistance Protein 1), expressed by CSCs in glioblastoma, is involved in the efflux of a variety of therapeutic compounds including methotrexate, edatrexate, ZD1694, doxorubicin, daunorubicin, epirubicin, idarubicin, etoposide, vincristine, vinblastine, paclitaxel, irinotecan, SN-38, flutamide and hydroxyflutamide [54,55,56].