MYCN and neuroblastoma: Immature or poorly differentiated neuroblasts matched tumor cells of the high-risk group, especially MYCN-amplified NB cells, and were associated with poor prognosis, while mature or highly differentiated neuroblasts matched NB cells of the low-risk group and MYCN-nonamplified tumor cells and were associated with good prognosis [44, 45, 72, 86].