Comparative analyses of the immune cell infiltrates in RLNTs and primary cHLs. To quantify differences between RLNTs and cHL specimens, the number of cells that each contributed to a given cluster was determined. Clusters were defined by lineage, differentiation, and polarization status. For each cluster and shared category, the RLNT and cHL median cell count was calculated and presented as comparison pie charts. (A) All viable cell clusters, >5% of sampled events per cases. (B) CD3⁺ T cell clusters, >5% of sampled events per case. Clusters that are statistically significantly different in cHLs and RLNTs are marked with an asterisk (*; see supplemental Figure 4). (C) Relative differences in CD4⁺ Teff (lower panels) and Treg (upper panels) subsets between RLNTs and cHLs. The relative proportions of each subset are represented by the sizes of the circles, and the color scheme is the same as in (B). PD-1 expression levels for each CD4⁺ T-cell subset are indicated below the respective circle and are based on the color bar shown at the bottom of the panel. cHLs have increased numbers of Th1-polarized PD-1⁻ Tregs and more differentiated PD-1⁺ Th1 effector cells.