In a mouse acute infection model of influenza virus, CD4 CTLs are detected in both the CD27+ and CD27− populations (46), and the majority of Eomes+ CD4 CTL expresses CD27 in an experimental autoimmune encephalomyelitis (EAE) model (47), indicating that these molecules do not necessarily represent authentic markers for CD4 CTLs. The gene discussed is CD4; the disease is experimental autoimmune encephalomyelitis.