Previous studies in woodchucks have investigated selected aspects of the immune response and showed that resolution of WHV infection is associated with strong T-cell proliferation and IFN-γ and TNF-α expression during the early phase of infection, and with seroconversion to virus-neutralizing antibodies targeting WHV surface antigen (WHsAg), while progression to chronicity involves deficiencies in these T- and B-cell responses [12–14]. The gene discussed is TNF; the disease is infection.