PBX2 and neuroblastoma: Notably, exo-DNA at progression showed some variants in NB driver genes as CASZ1, PBX2, DMBT1, and PTPN11 [6], but even more importantly, exo-DNA at onset already displayed pathogenic mutations on the NB driver genes PTPN11 and FGFR1. The PTPN11 mutation was also present on tumor DNA at onset (Supplementary Table S1).