Due to more than 1500 sites in the Hepatitis B genome being multiple coding, we may reasonably test whether the simpler multiplicative model is an equally good fit to the full one used above. Setting f AB = f A ·f B we may perform a likelihood ratio test between the full and the restricted model, where selection acting on two different genes simultaneously gets multiplied up. With -2log Λ = 18 for 3 added parameters, the full model fits the date significantly better than the restricted multiplicative one (P = 0.0004).