A couple of years back a French research study (known as the Séralini.study after its primary author) claimed that rats fed a diet which contained a Roundup-tolerant genetically modified corn or the herbicide Roundup or a combination of the herbicide and genetically modified corn died more frequently and earlier over the two year study than control groups.
The paper was retracted after widespread criticism of its methodology and interpretation. It has now been republished in a new journal. However, despite some minor tweaks to the paper the major flaws in this study still remain. Basically, none of its claims are valid, indeed the entire study is uninterpretable.
This evidence shows that all we are seeing in this recycled paper is due to random variation in a poorly controlled experiment. It does not show that GMO corn, or roundup, even at concentrations that no human would ever be exposed to through diet, have any effect on cancer or mortality.
Read the full, original article: An anti-GMO article rises from the grave