Importantly, we found that acute HIV-1 infection in BLT mice resembled human HIV-1 infection, since there was loss of IL-21-8, 36 and IL-17A-producing35, 37 CD4 T cells reflected in the downregulation of IL21 and IL17A mRNAs and proteins from CD4 T cells (Fig. 6c,d). The gene discussed is IL21; the disease is HIV-1 infection.