CD34 and leukemia: Increasing evidence based on maturation-dependent antigens, including CD34, CD10 and CD20, suggests that there is no stem cell hierarchy in pediatric B-ALL.8, 9, 11 NG2 is specifically expressed in MLLr leukemia but its function remains enigmatic.14, 15 Here we addressed whether NG2 expression defines a blast population enriched in L-IC activity.