The lower exposure in glioma patients may reflect baseline patient-specific factors or disease characteristics in this population, such as lower age, less frequent use of CYP3A4 inhibitors, more frequent use of strong CYP3A4 inducers (e.g., carbamazepine and phenytoin), and adequate renal/hepatic function, as compared with patients with cholangiocarcinoma/chondrosarcoma. This evidence concerns the gene CYP3A4 and central nervous system cancer.