Aspirin therapy is associated with reductions in serious vascular events, including stroke and coronary events, and a 10% reduction in total mortality [9,67] A positive effect in the context of secondary prophylaxis was also demonstrated with another antithrombotic medication, namely with a P2Y12 inhibitor clopidogrel [68] Which of the two substances, aspirin or clopidogrel, is better suited for secondary prevention could be answered by meta-analysis of comparative studies. The gene discussed is P2RY12; the disease is Stroke.