MYCN and neuroblastoma: Initial cell viability assays were carried out using the MYCN-amplified neuroblastoma cell line UKF-NB-3, established from a stage 4 neuroblastoma patient25 and the vincristine-resistant UKF-NB-3 sub-line UKF-NB-3rVCR10 (adapted to growth in the presence of vincristine 10 ng/mL).