MAPK3 and Stroke: Folic acid can inhibit ERK1/2/NOX4/ROS pathway to reduce peroxide production, enhance antioxidant enzyme activity to attenuate oxidative stress and inflammation, and thus play a protective role on stroke.35 More importantly, folic acid may alleviate thromboxane A2 release and clotting factor expression by decreasing tHcy, thereby reducing platelet activation and thrombosis, and ultimately preventing stroke.