Following ON-CR at 6 weeks of age (Fig. 2a), Nf1OPG mice exhibit increased optic nerve volumes (Fig. 2b), tumor proliferation (%Ki67+ cells; Fig. 2c), cell density (Additional file 2: Fig. S2a) and GFAP expression (Additional file 2: Fig. S2b) at 12 weeks of age, relative to sham controls. This evidence concerns the gene GFAP and neoplasm.