MYCN and neuroblastoma: The importance of MDM2 in neuroblastoma pathogenesis is further illustrated by studies which have observed that a SNP within the MDM2 promoter (SNP309T to G) that can lead to higher expression of MDM2 and greater inhibition of p53, is associated with poor survival in neuroblastoma, in particular stage 4 patients with MYCN amplification (Cattelani et al., 2008; Perfumo et al., 2008, 2009).