Lactoylglutathione lyase, also known as Methylglyoxalase, Aldoketomutase, Glyoxalase I, Ketone-aldehyde mutase, S-D-lactoylglutathione methylglyoxal lyase and GLO1, is a member of the glyoxalase I family. GLO1 / Glyoxalase I is a ubiquitous cellular defense enzyme involved in the detoxification of methylglyoxal, a cytotoxic byproduct of glycolysis. Accumulative evidence suggests an important role of GLO1 expression in protection against methylglyoxal-dependent protein adduction and cellular damage associated with diabetes, cancer, and chronological aging. GLO1 / Glyoxalase I has been implicated in anxiety-like behavior in mice and in multiple psychiatric diseases in humans. GLO1 / Glyoxalase I catalyzes the conversion of hemimercaptal, formed from methylglyoxal and glutathione, to S-lactoylglutathione. GLO1 / Glyoxalase I exists in three separable isoforms which originate from two alleles in the genome. These correspond to two homodimers and one heterodimer composed of two subunits showing different electrophoretic properties. GLO1 upregulation may play a functional role in glycolytic adaptations of cancer cells.