Verboeket SO, Wit FW, Verheij E, et al. - Considering their reports that people living with HIV (PWH) with suppressed viremia (predominantly men who have sex with men (MSM)) exhibit similar T-cell senescence when compared with HIV-negative otherwise comparable controls, but had greater T-cell senescence than healthy blood donors, researchers here compared CD4⁺ and CD8⁺ T-cell counts and CD4⁺/CD8⁺ ratios between HIV-negative MSM and men who only have sex with women (MSW). Further, they related the observed differences to behavioral factors and infectious exposures, including cytomegalovirus (CMV) infection. T-lymphocyte phenotyping was conducted 3 times biennially in 368 HIV-negative MSM and 72 HIV-negative MSW. MSM vs MSW, exhibited higher CD8⁺ counts (551 vs 437 cells/mm³), similar CD4⁺ counts (864 vs 880 cells/mm³) and lower CD4⁺/CD8⁺ ratios (1.84 vs 2.47). MSM with > 10 recent sex partners showed the most pronounced differences, and this is partly explained by higher CMV seroprevalence in MSM.