MYCN and neuroblastoma: Roniciclib treated NB cells displayed a marked decrease in protein expression for the surface stem cells markers CD44v6, CD114, (Figs. 5 and 6) and for the CD44v6 ligand Osteopontin (OPN) too55, more evident in the MYCN not amplified cell lines ACN and SH-SY5Y (Fig. 5).