Studies on exosomes related to ACS have been focused on plasma exosome profiling in STEMI patients with and without out-of-hospital cardiac arrest compared with chronic coronary syndrome [8], and assessed the potential of the exosome Cyr61 as a diagnostic biomarker for ACS, explored the role of Cyr61 in vascular remodeling in vitro [4], and the protective and repair effects of pericardial fluid exocrine clusterin on cardiomyocytes after MI [15]. The gene discussed is CCN1; the disease is cardiac arrest.