Another year, another controversy: that was the story in the perennially contentious area of genetically modified (GM) crops. In 2002, arguments centred on David Quist and Ignacio Chapela's study of Mexican maize. It was simultaneously a bitter ideological feud among biologists at a single US university and a flashpoint between the agribiotech industry and anti-GM activists over the acceptability of transgenic crops in the developing world — which is becoming a key battleground. And it illustrated how, in this field, the quest for scientific truth is conducted in a minefield of opinion and accusations of vested interests.