Studies were conducted to evaluate the toxicity of MON810 maize and Cry1Ab protein. Quails were fed with corn grains of the MON810 lineage with up to 10% of the weight of whole grain corn bran in the diet, and no adverse or toxic effects were observed. Sanden et al. (37) concluded that MON810 corn, added to 12% in fish feed, was as safe as non-transgenic varieties, evaluating parameters of the intestinal tract of Atlantic salmon. Food safety studies for mammals were carried out with the protein expressed in E. coli, which proved to be chemically and functionally equivalent to that expressed in the MON810 strain, as well as in a microbial pesticide formulation (DIPEL) containing B. thuringiensis. Acute oral toxicity studies for mice showed that the level reached, with no observed effects, was 4000 mg/kg of body weight and an LD50 higher than this value was proposed. A recently published study that evaluated the sub-chronic (90 days) toxicity of Guardian corn in rats showed that the addition of MON810 corn at levels of 11% and 33% in balanced diets did not cause any change in animals fed the genetically modified variety. when compared with the unmodified strain(24). Shimada et al.(39) demonstrated the absence of toxicity of the Cry1Ab protein on isolated bovine hepatocytes, suggesting that the protein has low acute toxicity for mammalian cells.