A6770 is an inhibitor of sphingosine-1-phosphate (S1P) lyase.1It induces accumulation of [3H]sphinganine-1-phosphate ([3H]dhS1P), an S1P lyase substrate, in IT-79MTNC3 cells that endogenously express high levels of S1P lyase (EC50= <0.01 μM), an effect that is reduced in the presence of vitamin B6(EC50= <100 μM).