CYM50308 (ML248) is a potent, selective and high affinity sphingosine-1-phosphate receptor 4 (S1P4-R) agonist with an EC50 of 56 nM. CYM50308 displays 37-fold more selective for S1P4-R than S1P5-R. CYM50308 has no activity at S1P1-R, S1P2-R and S1P3-R subtypes at concentrations up to 25 μM[1].