TNF and Sepsis: Reasons for these discrepant findings are probably multi-factorial and depend amongst others on the sepsis model used: Although our model demonstrated a peak in TNF-α and IL-6 expression at 6 h post CLP in both strains, Bougaki et al. [3] observed an increase in TNF-α as well as IL-6 expression at 22 h after colon ascendens stent peritonitis and genetic eNOS deficiency was associated with enhanced induction of proinflammatory cytokines.