The coiled-coil domain is a structural motif found in proteins that are involved in a diverse array of biological functions such as the regulation of gene expression, cell division, membrane fusion and drug extrusion and delivery. CCDC34 (coiled-coil domain containing 34), also known as Renal carcinoma antigen NY-REN-41, is a 373 amino acid protein that is expressed in testis, breast, lung, placenta, liver and small intestine. A translocation between the short arms of chromosomes 11 and 18 affecting the CCDC34 gene has been identified in a patient with hamartoma of the retinal pigment epithelium. There are two isoforms of CCDC34 that are produced as a result of alternative splicing events.