Keywords: S1P; sphingosine-1-phosphate; HDL-S1P; HDL-bound S1P; albumin-S1P; albumin-bound S1P; AKT; protein kinase B; SPHK; sphingosine kinase; PI3K; phosphatidylinositol 3-kinase; S1PR1-3; S1P receptor 1-3; RAC-1; ras-related C3 botulinum toxin substrate 1;