Quantification of proliferation by Ki67 image processing of virtual slides. (A) Ki67-stained wound cultures were separated into 10 regions of identical size equaling five concentric rings. The wound area was divided into four regions (d–g), whereas unwounded areas surrounding the wound were divided into three regions (a–c; h–j) at each side of the wound. Broken lines denote the wound margin. (B) The epidermal proliferation index (EPI) and the total number of Ki67⁺ cells were spatially and temporally evaluated by analyzing each region independently. The wound region is highlighted in gray. The red dotted lines represent the baseline levels of the epidermal proliferation index. The data shown are from a single representative experiment out of two repeats; n = 2 (day 0 [d0]), 3 (day 1), 3 (day 2), 3 (day 3), 3 (day 4), 3 (day 5), 2 (day 6), and 3 (day 10); 113 slides were analyzed in total; data are means. Bar, 1 mm.