. . . . . "Treatment of uninfected and acutely or chronically infected MT-4 and H9 T-cells with exogenous HIV-1 Nef downregulates the expression of CD71" . "HIV-1 Nef modulates the trafficking of transferrin receptor (TfR), the prototypical recycling surface protein, with the dileucine motif (amino acids 164-5) in Nef being required for this alteration of TfR recycling" . "downregulates" . "modulates" .