In nu/nu mice, there was no difference in serum concentration of AST (naïve: 93.8 ± 27.1 IU/L, Pb-infected: 179.4 ± 21.2 IU/L) and ALT (naïve: 33.8 ± 3.3 IU/L, Pb-infected: 45.6 ± 04.3 IU/L) between naïve and Pb-infected mice, whereas the serum concentrations of AST and ALT were significantly higher after Pb-infection in WT mice (naïve: 134.4± 27.7IU/L, Pb-infected: 593.2 ± 150.3 IU/L for AST; naïve: 36.6 ± 2.6 IU/L, Pb-infected: 128.4 ± 28.4 IU/L for ALT). The gene discussed is GPT; the disease is infection.