TNF and infection: PBMC cytokine expression during infection was depressed by dietary ID, especially production of the antiviral cytokine IFNG. Liver cytokine production was differentially modulated by diet during infection, with interactive effects producing both reduced TNF expression and increased IL1B expression in PID piglets compared to PN piglets, while PID liver IFNG expression (Figure 4D) was not depressed by ID as in PBMC (Figure 4B).