Carrying HLA-DRB1*04 in that sense represents a predisposition to autoimmunity; as such, autoimmunity could be mediated at least in part by CD28null CD4 T cells recognising a CMV epitope in this MHC context; however, to our knowledge, no CMV peptide presented by HLA-DRB1*04 has been reported to date. The gene discussed is CD4; the disease is Autoimmunity.