GW 4869 is a cell-permeable, non-competitive inhibitor of neutral sphingomyelinases (IC50 = 1 μM), but does not affect acid sphingomyelinase activity. It inhibits TNF-α-mediated sphingomyelin hydrolysis (100% inhibition at 20 μM) and TNF-α-induced cell death in MCF7 cells without interfering with activation of NF-κB or glutathione depletion in response to TNF. MW: 577.5. Purity ≥90%