Lectins are gene products from plants that are toxic to animals, including mammals.
Normally their levels are very low. Their toxicity to the human immune system is well established at such levels. Lectins have already been proven to be carcinogens. Celery with increased insect-fighting abilities has already been shown to cause cancer in mice and health problems to grocery store workers and field workers. Long term testing of the crops must be done to ensure safety, but before results are available, the crops should be labeled in the market so that people know, because there are potential health risks.