Treatment of mice with FTY720, a pro-agonist of multiple S1P receptors, including S1PR1, or with KRP203, a pro-agonist of S1PR1 and S1PR4 [33] has been reported in some studies to reduce atherosclerosis development in Ldlr KO mice induced by high cholesterol diet feeding [24,26]. This evidence concerns the gene S1PR4 and atherosclerosis.