GATM and brain neoplasm: The rationale for the present studies is the high rate of anticancer activity noted following treatment of patients with malignant brain tumours with more protracted, low-dose temozolomide schedules (Newlands et al, 1992; Brock et al, 1998), as well as the hypothesis that the administration of DNA methylating and chlorethylating agents on protracted schedules may progressively lead to greater inactivation of AGAT and inhibition of recovery of AGAT activity to a much greater extent than less protracted schedules.