The RING-type zinc finger motif is present in a number of viral and eukaryotic proteins and is made of a conserved cysteine-rich domain that is able to bind two zinc atoms. Proteins that contain this conserved domain are generally involved in protein-protein interactions and protein-DNA interactions. Specifically, they are thought to be involved in the ubiquitination pathway of protein degradation. RNF165 (RING finger protein 165) is a 346 amino acid protein that contains one RING-type zinc finger. Via its RING-type zinc finger, RNF165 may play a role in transcriptional regulation and protein degradation events. The gene encoding RNF165 maps to human chromosome 18, which houses over 300 genes, including Trisomy 18, or Edwards syndrome, the second most common trisomy after Downs syndrome. Translocation between chromosome 18 and 14 is the most common translocation in cancers, and occurs in follicular lymphomas. Niemann-Pick disease, hereditary hemorrhagic telangiectasia and erythropoietic protoporphyria are also associated with chromosome 18.