Median tumor volume at diagnosis accounted for 12.5 cm3 (0.04–68.5, n = 33), showing a higher median tumor volume in non-NF1 OPG as compared to NF-1 OPG, whereas no statistical significance could be shown (17.9 vs 4.9 cm3, p = 0.15, see Fig. 2A). The gene discussed is NF1; the disease is neoplasm.