Next, we wanted to study whether it was possible to affect the Notch-associated differentiation of NB cells using HDAC inhibitors, since a functional Notch cascade relies on HDAC activity for a normal function of both RBP-Jκ and Hes-1 (Grbavec and Stifani, 1996; Jimenez et al, 1997; Kao et al, 1998). This evidence concerns the gene RBPJ and neuroblastoma.