TP53 and cancer: Activated p53 induces the transcription of MDM2, which in turn targets p53 for proteolytic degradation; however, the MDM2-mediated p53 degradation pathway is switched off in HPV-infected cancer cells because of the persistent degradation of p53 by E6.31 As DHA-induced reduction in E6 derives from UPS activation, the observed p53 expression pattern could be attributed to the reactivation of p53, which is mediated by E6 inhibition, and the subsequent further degradation of p53 due to increased UPS activity.