MAPK3 and hepatitis B virus infection: We also found that T. gondii-induced ERK1/2 and JNK phosphorylation positively regulates IL-23 and IL-12 production, respectively; these results were similar to previously demonstrated that ERK1/2 activation is required for HBV viral protein HBx-induced IL-23 expression in hepatitis B virus (HBV) infection [32].