In addition to a lower prevalence of STAG2 mutations as established by the multivariable analysis, low-risk patients were characterized by younger age (mean age, 8.3 years in low-risk patients v 16.4 years in high-risk patients), smaller tumor volumes (proportion of evaluable tumors with volume ≥200 mL: 15 of 69 [21.7%] in low-risk patients v 10 of 25 [40%] in high-risk patients), and a higher proportion of extraosseous tumors (26 of 77 [33.8%] v 2/30 [6.7%]). This evidence concerns the gene STAG2 and neoplasm.