Fig. 1: Single-cell atlas of EBV-HLH patients, IM patients, and healthy volunteers.

a Flowchart describing the overall experimental design of this study. b UMAP was used for mapping 25,091 single cells from HV (n = 3), 56,752 single cells from IM (n = 9), and 134,973 single cells from HLH (n = 17). Based on the expression levels of marker genes, cells are categorized into ten distinct clusters and color-coded accordingly. c Expression distribution of canonical markers identifying individual cell clusters in the dot plot. The diameter of each dot reflected the proportion of subtype cells expressing a specific gene, while the color denotes the normalized mean expression. d The main cell lineages were labeled according to cell identity using canonical cell markers, as depicted in the UMAP plot. Color intensity ranging from gray to red indicates expression levels from low to high. e The enrichment of each cell subpopulation was quantified by calculating the ratio of observed to expected cell numbers (Ro/e). +++, Ro/e > 3; ++, 1.5 <Ro/e ≤ 3; +, 1 ≤ Ro/e ≤ 1.5; +/−, 0 <Ro/e < 1. f The scoring of cytokine sets for each cell in UMAP plot, with color intensity transitioning from blue to red to denote scores from low to high. g The scoring of inflammatory response sets for each cell in UMAP plot. The gradient from blue to red signifies expression levels increasing from low to high.