This year you stand in a historical position to prevent irreversible damage to one of the World’s most precious resources: Mexico’s maize diversity. We observe that your Administration may be rushing to introduce genetically modified (GM) maize into the Mexican environment and we are convinced, from our understanding of the scientific evidence, that this move represents a disproportionate risk which should be avoided for the benefit of Mexico and the World. Joined together in our well-informed concern, we urge you to move aggressively to ensure that no GM maize is planted in Mexico, the Center of Origin and Diversification of this important crop.