Plasma cytokine concentrations for interferon-γ (IFN-γ, A), tumor necrosis factor-α (TNF-α, B), interleukin-1α (IL-1α, C), interleukin-1β (IL-1β, D), interleukin-2 (IL-2, E), and interleukin-10 (IL-10, F) in PKU mice fed AA and GMP diets and in WT mice fed casein and GMP diets from weaning through 8–9 wk of age. Values are means + SE, n = 6–8.