Most GMO food safety concerns center around the proteins made by genetically engineered plants and animals. Why proteins? The DNA (genes) in the food we eat is broken down in our gastro-intestinal systems. As a plant or animal grows, however, it uses its the DNA to produce proteins. When we eat, our bodies break down most proteins, but not necessarily all. So, researchers must scrutinize the proteins being made by GMO plants and animals to see if they differ from their non-GMO counterparts. Three main concerns have surfaced. We list those, as well as the response of the United States Food and Drug Administration (FDA), a group that is responsible for making sure these products meet safety regulations in this country.