Wefound that the breadth of the response narrowed as the CD4 count declined and that,specifically, the contribution of Gag responses to the overall response decreased.It has previously been reported that acute HIV infection is associated with narrow,high affinity T cell responses which broaden as patients progress into chronicinfection [37].Here, we see the reverse of this process with a return to a much narrower range of Tcell responses. The gene discussed is CD4; the disease is HIV infectious disease.