An analysis of blood plasma samples (Table 3) revealed that the effect of infection, which was not associated with the diet × challenge interaction, caused an increase in the concentrations of endonuclease-1 (APEX-1) in birds infected with C. perfringens (P = 0.043) and 8-OHdG in birds challenged with C. perfringens or LPS, relative to unchallenged birds (P < 0.001); IgY concentration was lowest in turkeys administered LPS (P < 0.001); Cp concentration was higher in birds not infected with C. perfringens than in infected birds (P = 0.005). The gene discussed is APEX1; the disease is infection.