MDM2 and cancer: Moreover, miR-339-5p [26] and miR-661 [27] also promote p53 activity and stabilities by targeting MDM2 and/or MDM4, while miR-122 [28], miR-885-5p [29] and miR-542-3p stabilise p53 in cancer cells by disrupting MDM2-mediated p53 degradation [30].