(A to C) Left: WT and TRAF3-deficient HuT28 human T cells were stimulated with type I IFN I (1000 U/ml) for the indicated times. The indicated proteins were immunoprecipitated (IP) from cell lysates, and associated proteins or whole-cell lysates (input) were analyzed by Western blotting. Right: Quantification of the relative amounts of the indicated proteins from multiple replicates. Western blots are representative of three (A), eight (B), and six (C) biological replicates from the same number of independent experiments. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001; n.s., not significant by unpaired t test (A and C) or two-way ANOVA with Sidak’s multiple comparisons test (B). Error bars represent the SEM.