MDM2 and neuroblastoma: In contrast, the proportion of neuroblastoma tumors with aberrations in the p53/MDM2/p14ARF pathway which are MYCN amplified are lower than in cell lines (Corvi et al., 1995; Gonzalez-Gomez et al., 2003; Su et al., 2004; Spitz et al., 2006; Caren et al., 2008; Carr-Wilkinson et al., 2010), therefore it is possible that these abnormalities are selected for during the in vitro establishment and/or maintenance of these cell lines.