**Figure 8. **Histological assessment of disease severity correlates with degree of chimerism. Linear regression of the number of pixels
in the retrolental mass (RLM) versus *Arf *^{−/−} contribution, accounting for clustering of the eyes, showed good correlation for tailed-derived DNA (**A**) and the retinal pigment epithelium (RPE) (**B**) (Pearson correlation coefficients = 0.63 [p = 0.001] and 0.61 [p = 0.007], respectively), but not the cornea (**C**; Pearson correlation coefficient = 0.35, p = 0.101).