LAG-3 expression on NK cell subsets. (A) Representative ex vivo surface staining of NK cell subpopulations and (B) LAG-3 expression on CD56dimCD16+ NK cells. (C) LAG-3 expression on the CD56dimCD16+ and CD56hiCD16- NK subsets among healthy and HIV-infected groups. (D) Paired analysis of LAG-3 expression across NK subsets among HIV-N participants. Statistical comparisons made by Kruskal-Wallis (with Dunn’s or Mann–Whitney post-test) or Friedman test. *p < 0.05, **p < 0.01.