TNF and infection: The associations between TNFα mRNA (P = 0.03) and subsequent infection were independent of the duration of the operation whereas the associations between IL-23 (P = 0.44), RORγt (P = 0.43), FOXP3 (P = 0.49), IL-12 (P = 0.60) and T bet (P = 0.11) mRNA and subsequent infection were not.