CD4⁺T-cell subsets mediate coordination of the immune response in HR-MDS patients responding to AZA. (A-B) Pairwise correlations and hierarchical clustering of pretreatment peripheral blood (PB) and bone marrow (BM) blasts, absolute neutrophil count, and T-, and NK-cell frequencies in responders (n = 27) (A) and nonresponders (n = 25) (B) to AZA. The heatmap of responding patients revealed several coordinated modules indicating a coordinated immune response, whereas no modules were formed in nonresponders when frequencies were clustered either spontaneously (i) or ordered from responders (ii). (C) No numerical differences in CD4⁺ T-cell subpopulations were observed between responders and nonresponders. (D) Adjacency matrix from panel A arranged by connectivity. Three CD4⁺ T-cell subpopulations emerged on the top 4 ranking positions. CD4⁺ T cells are in white; CD8⁺ T cells are in light blue.