WNT signaling is active in human sclGVHD. (A) Skin sections from healthy volunteers, patients after allogeneic transplantation without GVHD, and patients with cGVHD (original magnification ×100; hematoxylin and eosin stain; scale bars, 250 μm). (B-D) Immunofluorescence analyses of nuclear β-catenin: β-catenin was detected by immunofluorescence staining in skin biopsies of patients with cGVHD, patients with allogeneic transplantation without GVHD, and healthy volunteers. Fibroblasts were identified by staining with P4Hβ. Representative images of patients with cGVHD and controls (original magnification ×400). (B) Nuclear β-catenin expression was increased in the dermis of patients with cGVHD (sclGVHD; n = 4) compared with patients with allogeneic transplantation without GVHD (n = 6) and healthy volunteers (n = 8). Boxes denote the area of panel C. (C) Voronoi tessellation of nuclear β-catenin⁺ fibroblasts. (D) Percentage of nuclei β-catenin⁺ fibroblasts in the skin of patients with sclGVHD, patients with allogeneic transplantation without GVHD, and healthy volunteers. (E-G) RNASeq analysis of 6 sclGVHD patients and 4 healthy controls. **P < .05; ***P < .01. (E) Heat map illustration of DEGs. (F) Volcano plot. The expression of each gene is plotted as the log₂ fold change in expression against −log₁₀ (false discovery rate [FDR]); the black dotted lines indicate thresholds of FDR, 0.2 and fold change, 1.5. Differentially regulated genes with FDR <0.2 and fold change >1.5 compared with controls are shown in red (upregulated) and green (downregulated). (G) Bubble plots displaying significant enrichment of GO biological processes. The color of the bubble represents the P value, and the size of the bubble represents the number of DEGs in the data sets associated with the GO processes.