Presence of PI3K and phosphorylated ERK proteins. Liver samples obtained from the 4 groups of mice were analyzed for the (A) PI3K and (B) phosphorylated ERK (ERK-p) proteins. The quantified results of PI3K/actin and ERK-p/actin ratios were shown in the lower panels, respectively. *, # and ¥ indicate significant differences as compared to the PBS, IgG, or B19-NS1 group, respectively. Similar results were obtained in three independent experiments.