An inhibitor of caspase-8 (IC50 = 5 nM); inhibits fluticasone propionate-induced increases in apoptosis in peripheral blood T-cells isolated from patients with asthma at 60 μM; inhibits increases in hepatic caspase-3 activity, DNA fragmentation, cytosolic cytochrome c levels, and proteolytic processing of caspase-3, -8, and -9 proenzymes in a mouse model of Fas-induced apoptosis and liver failure at 10 mg/kg