TP53 and neoplasm: Interestingly, in p53-mutated or missing tumor cells, iASPP can bind p73 and inhibit apoptosis, and 37 amino acid (37AA), a p53-derived hybrid peptide derived from conserved box II (residues 118-142) and III (residues 171-181), dissociates such a binding and reverses the inhibition [10, 11].