Distribution of deep functional signatures across CMV clinical groups. Deep immunophenotyping based on expression of IFN-γ, ΜIP-1β, TNF-α, and/or IL-2 was used to delineate fifteen functional populations within the CMV(pp65)-specific CD8⁺ T-cell compartment (n = 42): 1 functional subset was a quadruple producer; 4 subsets were triple producers; 6 subsets were double producers; and 4 subsets were single producers. Mean and standard error of the mean for each signature in the 3 patient groups are shown. Dotted boxes show the NPS (IL-2⁻IFN-γ⁺TNF-α⁻ΜIP-1β⁺) and the PS (IL-2⁺IFN-γ⁺TNF-α⁺ΜIP-1β⁺) were found to be associated with increased and reduced risk of CMV reactivation, respectively, in analyses shown in Figures 5 and 6 and Table 2. EC (n = 13); SC (n = 16); NC (n = 13).