International Journal of Toxicology May 2007 26(3):31-77 Generally recognized as safe and effective a suppressive effect on tumors strong suppressive effect on some tumors Generally recognized as safe and effective International Journal of Toxicology May 2007 26(3):31-77 Generally recognized as safe and effective International Journal of Toxicology May 2007 26(3):31-77 strong suppressive effect on some tumors International Journal of Toxicology May 2007 26(3):31-77 International Journal of Toxicology May 2007