CD4 and HIV infectious disease: In contrast to these results from our laboratory [14], [17], a recent study reported contradictory results, showing that HD5 inhibited HIV infection of primary CD4+ T cells under serum-deprived conditions (0.3% human AB serum, ITS supplement (Insulin, Transferrin, Sodium selenite), and IL-2), conditions which the authors thought simulated the mucosal environment [18].