Upregulation of CXCL9 and CXCL11 in MARs and evidence that these chemokines are macrophage derived in CTCL skin. (A) Volcano plot of differentially expressed genes in total skin at the time of skin rash compared with baseline showing upregulation of CXCL9, CXCL11, and IFI44L and downregulation of CCR4 in CTCL of 14 patients treated with mogamulizumab. (B) T-stochastic neighbor embedding (t-SNE) of single-cell RNA expression data showing the main cell populations in the skin and the expression of CXCL9, CXCL10, and CXCL11, mainly by macrophages, and CXCR3 by lymphocytes in patients with CTCL. (C) Coexpression matrix displayed as heatmap, confirming the expression of CXCR3 by cells that express lymphocyte markers and CXCL9 by cells that express macrophage markers. (D) Normalized expression values of CXCR3, CXCL9, and CXCL11 displayed according to cell type. (E) Raincloud plot displaying expression levels of CXCR3 by CD8 T cells and CXCL9 and CXCL11 by macrophages, listed by patient (healthy donor [HD] vs tumor-stage MF [TMF], erythrodermic MF [EMF], or SS). (F) Cell–cell communication pathways between the main cell compartments in advanced CTCL skin highlighting the antitumoral lymphocyte response and the key factors from the tumor microenvironment.