Fig. 2

CD4⁺ T cells in subepithelial and intraepithelial lesions of various histological grades of oral leukoplakia. Percentages of CD4⁺ T cells in subepithelial (a) and intraepithelial (b) lesions of various histological grades of leukoplakia are shown. Data are expressed as box plots indicating the maximum, median, and minimum values. Statistically significant differences were observed in intraepithelial lesions of the moderate and severe grades of dysplasia compared to cases without dysplasia (*p < 0.05, Dunn test). Correlation between infiltrated CD163⁺ and CD4⁺ cells in leukoplakia (c). Statistically significant differences were determined using Spearman’s rank correlation coefficient analysis (p = 0.0009). There were no statistically significant correlations between CD68⁺ and CD4⁺ cells (d) and CD80⁺ and CD4⁺ cells (e)