Scaffold assembly of TNFR1 complex and caspase 8 activation after violacein treatment. (A) TNFR1 was immunoprecipitated from HL60 cells and then lysates were subjected to Western blot to detect interacting proteins. (B) Cellular lysates were extracted from HL60 cells treated with 1000 nM violacein, infliximab (IFX; 0.1, 10, and 100 μg/mL) or violacein plus infliximab. Western blot analysis was performed to assess the processing of caspase 8.