Figure 8. The number of Ki67-positive cells found in the RPE flat mounts of pigmented animals sampled from embryonic day 18 (E18) through to postnatal day 150. Relatively few cells were in the cell cycle at E18, which is when the normal patterns of cell division in developing tissue end. However there was a marked increase (ANOVA, p<0.0001) in the number of these cells on the day of birth (0), which was statistically significant compared to E18 (Newman-Keuls, p<0.001). From P0 on, cell number gradually declined with age.