MYCN and neuroblastoma: To further validate the role of ATP13A3 in polyamine uptake in various neuroblastoma cells, we performed transient siRNA‐mediated ATP13A3 knockdown in both MYCN‐amplified (KELLY and BE(2)‐C) and non‐MYCN amplified (SH‐SY5Y) neuroblastoma cell lines (Fig. 5A, Fig. S6).