Transgenes from genetically modified (GM) maize (corn) crops have been found in traditional ’landrace’ maize in the Mexican heartland, a study says. The work largely confirms a similar, controversial result published in Nature in 2001 and may reignite the debate in Mexico over GM crops. The paper reports finding transgenes in three of the 23 locations that were sampled in 2001, and again in two of those locations using samples taken in 2004. Written by a team led by Elena Álvarez-Buylla of the National Autonomous University of Mexico (UNAM) in Mexico City, the study will be published in the journal Molecular Ecology.