Fig 1: RIPK3-induced apoptosis was dependent on RIPK1, FADD, and caspase-8.(A) Cultured MCF7/TO-RIPK3 cells were treated with DMSO or Dox plus the indicated agent for 24 hr. The cells were then harvested, and RIPK3 was immunoprecipitated from the cell lysates using anti-Flag resin. The cell lysates and immunocomplexes were analyzed by western blotting using antibodies as indicated. (B–E) Cultured MCF7/TO-RIPK3 (wild type [WT], RIPK1-/-, Caspase8-/-, FADD-/-, and cFLIF-/-) cells were treated with DMSO or Dox induction for 36 hr. Cell viability was determined by measuring cellular ATP levels (upper panel). The data are represented as the mean ± SD of triplicate wells. *p<0.05, ***p<0.001. p-values were determined by two-sided unpaired Student’s t-tests. The cell lysates were analyzed by western blotting using antibodies against RIPK1, caspase-8, FADD, cFLIP, or β-actin (lower panel). Five independent knockout clones were test in each gene.