NVP-LAQ824-induced apoptosis is caspase dependent. (A-B) MM.1S cells were incubated with 1 μM NVP-LAQ824 for 42 hours, with or without the pancaspase inhibitor ZVAD. Apoptosis at 42 hours was completely inhibited by ZVAD. Sub-G₁ (▪), G₁ (□), S (▧), and G₂ (▨). (C-E) A 24-hour incubation with NVP-LAQ824 resulted in cleavage of pro-caspases-8, -9, and -3. FL indicates full-length fragment; CF, cleavage fragment.