Researchers bred ApoE−/− mice with IL-17A-deficient (IL17a−/−) and IL-17 receptor A-deficient mice (IL17ra−/−) to determine the role of the IL-17A cytokine on atherosclerosis, and they observed a significant decrease in aortic plaque formation in IL17a−/−/ApoE−/− mice in comparison to chow-fed IL17a−/−/ApoE−/−, IL17ra−/−/ApoE−/− and ApoE−/− mice [64]. This evidence concerns the gene IL17A and atherosclerosis.