All these data suggest that IL-23 might play an important role in the pathogenesis of hepatitis B. However, the precise source cells of IL-23, the mechanism by which HBV induces their production of IL-23, and the concrete functions of IL-23 in hepatitis B patients have to be clarified in order to gain an accurate and useful understanding of the immunological mechanisms underlying HBV infection. This evidence concerns the gene IL23A and hepatitis B virus infection.