BRD4 and neuroblastoma: Since we could not detect any other major genetic aberration apart from a YAP1 amplification and a BRD4 amplification each in one case, we strongly assume that MYCN amplification is the main driving oncogenic event in SP-EPN-MYCNs as is also known for aggressive neuroblastoma, in which MYCN amplification is sufficient for tumor formation and progression [41].