a, Time line of siRNA and LPS/d-GalN administration. b, Tnf, Il1b, Il10 and Ccr2 mRNA expression in unstimulated PECs from mice gavaged with Scr- and Map4k4-siRNA-containing GeRPs (n = 3). Statistical significance was determined by a two-tailed Student’s t-test. c, d, Serum (c) and peritoneal (d) Tnf-α levels in siRNA-treated mice 1.5 h and 4 h after LPS/d-GalN administation (n = 10). Statistical significance was determined by ANOVA and Tukey post test; **P < 0.001 and *P < 0.05. e, Survival percentage of mice gavaged with PBS or Scr- and Map4k4-siRNA-containing GeRPs, followed by LPS/d-GalN administration (PBS, n = 11; Scr and Map4k4, n = 22). Statistical significance was determined by Kaplan–Meier analysis and Mantel–Cox testing (P < 0.01; see Supplementary Table 3). Results are the mean of three independent experiments. All results are mean ± s.e.m.