Figure 4. Squamous epithelial cell proliferation of does not correlate with age or rete ridge elongation. (A-C) Representative images of Ki67 staining. Donors were 32 (A), 49 (B), and 78 (C) years old. Bar=100 μm; brown, Ki67+ cells; blue, cell nuclei. (D-I) Numbers of Ki67-positive cells plotted against age (D-F) or rete ridge elongation (G-I). (D, G) Numbers of Ki67-positive cells per area of stratified squamous epithelium area (number/mm2). (E, H) Numbers of Ki67+ cells per surface length (number/mm). (F, I) Numbers of Ki67+ cells per length of the dermo-epithelial junction (DEJ) (number/mm). n=14; NS, not significant (Pearson's correlation test).