MDM2 and melanoma: This analysis showed that activation (in C2 and C4) and deactivation (in C3) of cell cycle genes appeared to be governed by downregulated or upregulated CDKN1A (cyclin-dependent kinase inhibitor), and the p53 antagonist MDM2, all involved in melanoma cell cycle de-regulation (Supplementary Figures S2, S4, and S5)2.