MDM2 and cancer: MDM2 is considered a primary mechanism to inhibit wild-type p53 as part of a self-regulatory loop, wherein each modulates the other's cellular levels; in more detail, MDM2 subverts p53-mediated apoptosis by marking p53 for processes like ubiquitin-mediated degradation; this shift in the balance of pro- and anti-apoptotic proteins allows cancer cells, which would normally undergo apoptosis, to survive and build resistance to treatment.112