(A) Inhibition of necroptosis alone does not restore growth of cells treated with JG-98. Cells were pretreated with necrosulfonamide (NSA, 20 μM) for 1 hour prior to addition of compounds. Error is SEM. (B) Inhibition of both apoptosis and necroptosis is necessary to fully suppress JG-98 activity. Cells were pretreated with both 40 μM z-VAD.fmk and 20 μM Necrosulfonamide for 1 hour prior to addition of compounds. Cell growth was determined by three independent MTT assays performed in quintuplicate. *p value < 0.05, **p value < 0.01, ***p value < 0.001, ns = not significant. (C) Jurkat cells were pretreated with z-VAD.fmk (40 μM), NSA, both, or necrostatin-1 for 1 hour prior to addition of JG-98 (10 μM). Inactivation of both apoptosis and necroptosis was necessary to prevent activity. Cell viability was determined by trypan blue exclusion. Results are the average of three independent experiments performed in triplicate.