EIF4EBP1 and HIV-1 infection: Evaluation over 12 hour intervals determined that the abundance of P-eIF4E and Ser65-phosphorylated 4E-BP1 (P-4E-BP1) were reduced by HIV-1 infection (see 36 hour), but not ΔVifVprX infection (Figure 6B, compare HIV-1 to ΔVV).