Fig. 3

Linear regression analyses of mitotic count and Ki67 proliferation index versus Smoothened (SMO) expression. (A–D) Number of mitoses per 10 high-power fields (HPFs; 400× magnification, field diameter 400 μm) plotted against SMO expression, measured as optical density (OD). (E–H) Ki67 index measured digitally in hot-spot areas with the highest ratio of Ki67-positive cells to total tumor cells, plotted against SMO expression. In basal cell carcinoma (BCC; A), SMO expression was significantly associated with mitotic count (R² = 0.50; slope coefficient = 2.97 mitoses per 0.1-OD increase; P = 0.002). No significant associations were found at the Bonferroni-corrected significance threshold (P < 0.01) in squamous cell carcinoma (SCC; B; R² = 0.13; P = 0.22), sebaceous carcinoma (SEB; C; R² = 0.29; P = 0.06), or across all diagnoses combined (D; R² = 0.01; P = 0.57). By contrast, SMO expression correlated significantly with Ki67 index in BCC (E; R² = 0.82; P < 0.001), SCC (F; R² = 0.52; P = 0.005), SEB (G; R² = 0.61; P = 0.002), and all diagnoses combined (H; R² = 0.53; P < 0.001).