(F) WT and TAK1Δ MEFs left untreated and treated with 250 or 500 ng/ml TRAIL were analysed for cell death by the LDH release assay. Similar results were obtained in two independent experiments (A, C and E). The values represent mean±s.d. for two (D) or a minimum of three independent experiments (B, F). *P‐value 0.05, **P‐value 0.01 and ***P‐value 0.001 as compared with cells treated in the same way, but transfected without siRNA (B, D) or the wild‐type cells (F). 