SMPD1 and hepatocellular carcinoma: First, we used myriocin (MYR, 5 μM), which targets ceramide de novo biosynthesis by inhibiting SPT; and imipramine (IMIP, 15 μM), tricyclic antidepressant and effective ASMase inhibitor [22], to block ceramide generation from the sphingomyelin pathway, at doses that caused no effect in hepatoma cell growing.