MGMT: A personal perspective

This review describes the history of studies on alkylation damage of mammalian genomes and its carcinogenic consequences that led to the discovery of a unique DNA repair protein, named MGMT. MGMT repairs O6-alkylguanine, a critical mutagenic lesion induced by alkylating agents. The follow-up studies in mammalian cells following the discovery of the ubiquitous repair protein in E. coli are summarized.