Fig. (2) The SPHK2 activity in A20/2J cells was inhibited by SG-12. A20/2J cells or A20/2J cells transfected with mouse SPHK1 or SPHK2 (2 × 10⁶ cells/ml) were incubated with or without SG-12 (2, 4, 8 µM) for 5 min and then with [3-³H]sphingosine for 5 min. Lipids were extracted and separated by TLC as described in “Materials and Methods.” [³H]Ceramide and [³H]palmitic acid moved with solvent front. Essentially the same result was obtained in another independent experiment.