ABCB1 and central nervous system cancer: So far, ANG2 has proven capable of delivering paclitaxel to glioma and brain metastases, avoiding P-glycoprotein-mediated paclitaxel efflux (90), and is currently in Phase II clinical trials for recurrent high-grade glioma (NCT01967810) and breast cancer with recurrent brain metastases (NCT02048059).