Apelin promotes vasodilation by activating the APJ receptor, which stimulates the production of several vasodilatory factors, such as NO and superoxide dismutase, in vascular endothelial cells.[36] Studies have found that the expression of the apelin signaling pathway in patients with coronary artery disease is negatively correlated with the occurrence of CAS.[37] These findings suggest that the apelin signaling pathway plays a crucial role in the onset and progression of cardiovascular diseases, particularly those associated with vasospasm. Here, APLN is linked to coronary artery disorder.