As expected, myelosuppression, particularly severe thrombo-cytopenia, was the principal dose-limiting toxicity of temozolomide in patients treated with the agent on both Schedules A and B. For patients treated on Schedule B, AGAT inactivation in PBMC was significantly greater in patients who experienced severe thrombocytopenia than in those who did not. Here, GATM is linked to Thrombocytopenia.