Comparison between the groups with wild-type and mutant p53 revealed a significantly decreased mRNA expression of two canonical p53 transcriptional targets, CDKN1A (p21) (P<0.01) [23] and MDM2 (P<0.001) [24] in the tumours with p53 loss of function mutations (Figure 1A and B). The gene discussed is CDKN1A; the disease is neoplasm.