MDM2 and breast cancer: Furthermore, ubiquitin ligases such as tripartite motif-containing 28 (TRIM28), RNF2, and Cul4a can also promote p53 degradation by cooperating with MDM2.35, 36, 37, 38 Other ubiquitin-related enzymes such as TRIM31 can form a competitive relationship with MDM2 and prevent MDM2 from interacting with p53, leading to p53 activation in breast cancer.39