Other known p53 target genes, such as CDKN1A (p21), GADD45A and MDM2 (Riley et al, 2008), did not show this strong correlation: for these genes, considerable overlaps were found between the normal colon and 'p53-mutated' tumor groups in individual samples (Figure 4D–F). The gene discussed is GADD45A; the disease is neoplasm.