In 2015, Ayyadurai published a paper that applied systems biology, which uses mathematical modeling, to predict the chemical composition of genetically modified (GM) soybeans, and whether or not they were substantially equivalent to unmodified soybeans.[23] The paper claimed that GM soybeans have lower levels of the antioxidant glutathione and higher levels of carcinogenic formaldehyde, making the modified soybean substantially different, contrary to previous safety assessments.[24] Shortly after publication, Ayyadurai embarked on a speaking tour of the U.S. At the National Press Club, he said that genetic modification had "fundamentally modified the metabolic system of the soy", disrupting the "beautiful way of detoxifying [formaldehyde]" present in non-GM soy.[25]