RNF123 and metastatic melanoma: To further demonstrate the utility of EpiMap, we focused on the RNF123 gene that was previously reported by ours and Ciechanover’s group as downregulated in metastatic melanoma and glioblastoma tumors.4,5 RNF123, also known as KPC1, is an ubiquitin E3 ligase involved in ubiquitination and proteasomal processing of NF-ĸB1 p105 precursor to generate p50.