CD169+ macrophages in human melanoma . (A) Immunostaining of CD169⁺ macrophages in human normal/non-lesional skin with magnified images of the area outlined (yellow rectangle). Stained for DAPI (blue), CD68 (cyan), FXIIIA (green), and CD169 (red). CD169⁺ CD86⁺-positive cells were indicated with yellow arrows. Representative image of four samples. (B) Immunostaining of CD169⁺ macrophages in melanoma lesions with magnified images of the area outlined (yellow rectangles, a and b). Stained for DAPI (blue), CD68 (cyan), FXIIIA (green), CD169 (red), and SOX10 (pink). CD169⁺ CD86⁺-positive cells were indicated with yellow arrows. Representative image of eight samples. (C) The ratio of CD169⁺ macrophages (CD169⁺ CD68⁺ FXIIIA⁺ cells) inside or outside of primary melanoma lesions. Wilcoxon matched-pairs signed rank test was used. (D) UMAP plot illustrating immune cells and nonimmune cells in human melanoma lesions, color-coded for distinction. Cells were annotated based on the following gene expressions: melanoma cells (MLANA, PMEL, MITF, and DCT), fibroblasts (COL1A1 and COL3A1), endothelial cells (VWF and PECAM1), T cells (CD3D and CD3E), B cells (MS4A1 and CD79A), natural killer (NK) cells (FGFBP2 and KLRD1), and macrophages (CD68, CD14, and LYZ). (E) Cells expressing SIGLEC1, LYZ, MRC1, MERTK, HLA-DRA, and CSF1R were plotted onto the UMAP of macrophages (cluster 22).