TRAF6 inhibits LPS-induced caspase activation independently of NF-κB activation. Double-transduced endothelial cells (as labeled) were treated with LPS (100 ng/mL) and CHX (50 μg/mL) for 8 hours and assayed for DEVD-pNA cleavage activity. Results are reported as fold increase over CHX-only-treated cells. Results shown are the mean plus or minus SEM of 3 independent experiments, each done in duplicate. ^*P < .01.