Expression of HMGB1 in epidermal tumors and normal skin by IHC EnVision (magnification × 400). (a) to (i). Positive expression of HMGB1 was located in the nucleus, cytoplasm, cell, and (or) intercellular space after stimulation of inflammation or cell necrosis. The red arrow shows HMGB1 expression in the epithelial intercellular space, the black arrow shows positive HMGB1 expression in epithelial cell nuclei, the orange arrow shows HMGB1 expression in the epithelial cell cytoplasm, the blue arrow shows HMGB1 expression in an inflammatory cell, and the green arrow shows HMGB1 expression in a vascular endothelial cell. (j). **P < 0.01 of HMGB1 in epithelial intercellular spaces in SK as compared in NS. (k). **P < 0.01 of HMGB1 in epithelial cell nuclei in NS and SK as compared in SCC. (l). **P <0.01 as compared HMGB1 in inflammatory cells in NS. The error bars show the standard error of the mean (SEM).