For example, in the case of the MHV68 gamma-herpesvirus mouse model, Stevenson et al. used antibody treatment to deplete different T cell subsets to show that the mice can survive MHV68 infection even when the CD8 T cell population was greatly diminished, whereas the concurrent removal of both CD4 and CD8 T cell subsets proved invariably fatal [19]. The gene discussed is CD4; the disease is infection.