Indeed, aspirin and non-steroidal anti-inflammatory drugs (NSAIDs), including inhibitors of COX-2 are effective in the treatment of pain and inflammation.9,10 However, the inhibition PGI2 production by the endothelium may contribute to the cardiovascular side effects of COX2 inhibitors.11 It is thought that inhibition of blood clotting by aspirin can reduce the risk of ischaemic events such as heart attacks and stroke, and prostacyclin analogues are used for the treatment of pulmonary hypertension.9,12,13. This evidence concerns the gene PTGS2 and pulmonary arterial hypertension.