With the use of transgenic crops expanding around the globe, we need to decide what level of unapproved plants we are willing to accept in our diets. Zero is not an option, says Heidi Ledford. Steve Linscombe still isn't quite sure how it happened. The director of the Louisiana State University AgCenter for Rice Research knows that he grew a few lines of transgenic rice in field trials between 2001 and 2003. He also knows that one of those lines, LLRICE601, was grown on less than one acre. What he is not clear on is how the line then wended its way into the food supply. That little mystery is now the subject of an official investigation and a class-action lawsuit.