In patients with postoperative infections, IL-12p70 is elevated in comparison with patients with no infectious complications.42 In our experimental conditions, low circulating concentrations of IL-12p70 coincided with peak levels of IL-10, a known regulator of proinflammatory cytokines.27 Thus, the high measured levels of IL-10 in serum on day 1 after laparotomy were in response to surgical trauma and gut manipulation with the goal of preventing an exaggerated inflammatory response.24 Here, IL10 is linked to infection.