The p53-MDM2/MDMX complexes have been well-characterizedas a target for cancer therapy.44,67,70 The UBA5 peptide (337EDNEWGIELVSEVSE351) isan unstructured region in crystal structures and the AlphaFold model,71 but it formed a small helix at the N-terminalin our simulations. This evidence concerns the gene MDM4 and cancer.