In addition to the several signaling pathways we mentioned above, proteasomes also regulate other tumor signaling pathways, such as the PI3K/Akt/mTOR pathway, the Notch pathway, and the Hedgehog pathway.96, 97, 98 There are also close links between different signaling pathways, for example, β-catenin overexpression protects p53 protein from MDM2-mediated proteasome degradation, thereby stabilizing p53 protein and increasing its transcriptional activity.99 This evidence concerns the gene TP53 and neoplasm.