Sphingosine-1-phosphate ( S1P ), the bioactive sphingolipid metabolite, is a critical regulator of many physiological and pathophysiological processes, including cancer, atherosclerosis, diabetes and osteoporosis. S1P and its receptors (S1P1-5) play critical roles in many pathologic processes, including cancer. S1P/sphingosine-1-phosphate receptor (S1PR) axis plays critical role in a wide variety...