Following HIV-1 infection with either X4- or R5- tropic viral strains, average relative fold change in CD4+ T-cell levels increased with EGFP+ cells (up to ∼1.5 and ∼2.1, respectively), but decreased with mCherry+ cells (up to ∼1.8 and ∼2.6, respectively), with statistically significant differences in relative fold changes between EGFP- and mCherry- marked CD4+ T-cell levels appearing as early as week 8 post-R5-tropic HIV-1 infection and week 4 post-X4-tropic HIV-1 infection (Figure 7). This evidence concerns the gene CD4 and HIV-1 infection.