CD4 and AIDS: To evaluate whether IL-2 expressing cells and TFR are found in the follicles and germinal centers of lymph nodes where the majority of TFH reside, inguinal lymph node sections of individuals with untreated chronic HIV infection without AIDS were evaluated for IL-2 and CD4 expression by in situ hybridization for mRNA, and FoxP3 by antibody staining (Figure 7).