CD4 and cancer: Chronic viral infection and cancer have similar immunosuppressive effects.37,60 HIV-1 infection leads to the TRAIL-mediated apoptosis of uninfected CD4+ T cells in NOD-SCID mice reconstituted with human PBLs.61 Human pDC can be transformed into IFN-producing killer pDC (IKpDC; a population with many similarities to murine pre-mNK cells) by exposure to HIV-1.