MTIC is a DNA alkylating agent, an active metabolite of dacarbazine, and an active degradation product of temozolomide.[1],[2],[3] MTIC is cytotoxic to L-cells and decreases thymidine and uridine uptake by 55 and 65%, respectively, when used at a concentration of 1 mM.[2] It is also cytotoxic to TLX5 murine lymphoma cells in a concentration-dependent manner.[3] In vivo, MTIC induces formation of mammary adenofibromas in rats when administered at a cumulative dose of 890 mg per animal over 14 weeks.[4]