The present invention provides compositions and methods for treating hepatitis B virus (HBV) infection as well as methods for identifying a compound or a composition that is suitable for treating HBV infection. In addition, the present invention provides a suitable non-mammalian animal model that can be used to screen for a compound or a composition that can inhibit HBV replication or treat HBV infection in a mammal. In particular, the present invention provides compositions and methods for treating hepatitis B infection by inhibiting interaction between HBV x protein and a Bcl-2 family protein or by reducing the expression level of a Bcl-2 family protein.
