MDM2 and neoplasm: It acts as a transcription factor, binding to DNA to induce the expression of proteins involved in cell cycle arrest, apoptosis, and DNA repair, while suppressing transcription of cell survival genes, such as BCL-2 and MCL-1.1,2 The importance of p53 in preventing the progression of tumours is well documented; the gene is found to be either inactive or mutated in approximately 50% of human cancers.3–6 In cases where wildtype p53 is present, its activity is suppressed through various signalling pathways,7 most notably through the action of MDM2, its key negative regulator.