MYCN and neuroblastoma: Substantial cytotoxicity was observed in MYCN-amplified neuroblastoma Kelly cells but not in unamplified SK-N-AS cells (Figure 3a) because MYCN plays a key role in the survival of MYCN-amplified neuroblastoma cells but not in unamplified ones [12,13] Additionally, a significant increase in DNA damage and replication stress was observed, as indicated by cytosolic dsDNA granules and IFN-α and IFN-β (Figure 4a,b).