PES1 and neuroblastoma: Roniciclib treatment caused nucleolar fragmentation (Fig. 6), with the consequent translocation and redistribution of the nucleolar proteins NPM1 and PES1 in most NB cells (ACN 98 ± 4%, IMR-32 88 ± 2%, and SH-SY5Y 84 ± 2% respectively, Supplementary Fig. S3), as well as the almost disappearance of NCL+ and GPC2+ cells (Fig. 6).