<p>U87MG-CD4<sup>+</sup>/CXCR4<sup>+</sup> cells (upper panel) and CEM-T4 cells (lower panel) were infected with wild-type HIV-1 NL4-3, a Nef-defective mutant (ΔNef), or the indicated Nef chimeras as described in the legends to <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0032561#pone-0032561-g007" target="_blank">Figures 7</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0032561#pone-0032561-g008" target="_blank">8</a>. DFP-4A, DFP-4AP, or DFP-4AB were added to the cultures to a final concentration of 3 µM, and viral replication was determined by p24 ELISA 5 days (U87MG) or 10 days (CEM-T4) later. Data are expressed as the mean percent of HIV-1 replication observed in control cultures incubated with the carrier solvent (0.1% DMSO) ± S.D. (n = 6).</p