S1PR1 and Myocardial fibrosis: ADMSC-sEVs have also been shown to activate the sphingosine-1-phosphate (S1P)/sphingosine kinase 1 (SK1)/sphingosine-1-phosphate receptor 1 (S1PR1) signaling pathway, thereby inhibiting the expression of NF-κB p65 and TGF-β1 [357], ultimately reducing myocardial inflammatory responses and myocardial fibrosis.