TP53 and neoplasm: Proof of concept for this was established using synthetic peptides and protein aptamers, while nutlins were identified as the first selective Mdm2 inhibitors that displaced p53 from Mdm2 (Chene, 2003; Vassilev, 2007) The nutlins have since then been shown to inhibit tumour growth and cause tumour shrinkage at non-toxic doses in mouse models (Vassilev et al, 2004; Tovar et al, 2006).