The FDA currently does not have a reliable way to assess the safety of food and products containing genetically modified organisms (GMOs). GMOs are now found in more than 80% of (non-organic) foods sold in conventional grocery stores in the U.S.  This study published in the International Journal of Biological Sciences, states:

The biological plausibility of a subchronic or chronic side effect of the GM diet, linked to the new toxin in the mammalian regimen, or due to the mutagenesis effect of the genetic modification itself, is thus non negligible. Finally it should be stressed that statistically significant effects of GM diets, or of residues of pesticides that are contained by GMOs, have also been observed in other instances [2125], but not in all studies [26, 27] enlightening the necessity of a case-by-case approach, and that the real toxicological studies are quite limited up to date for that [28]. All these observations taken together in our opinions do not allow a clear statement of toxic effects, but to suggest them as such, because they are clearly undeniable.

In English, that means there are certainly more risks and indications of caution around GMOs than previous claims from a Monsanto-supported expert panel.  The research, conducted by scientists from France, Italy, New Zealand, U.K. and U.S., corroborates the decade-long criticism by public interest organizations.  This is an important step, but I wish it would have been done before GMOs flooded the U.S. market.  This is another case that supports the purchase of organic produce — currently, produce that is certified organic can not be genetically modified.