The tripartite motif (TRIM) family of proteins are characterized by a conserved TRIM domain that includes a coiled-coil region, a B-box type zinc finger, one RING finger and three zinc-binding domains. TRIM8 (tripartite motif containing 8), also known as GERP (glioblastoma-expressed RING finger protein) or RNF27 (RING finger protein 27), is a 551 amino acid protein that is thought to function as an E3 ubiquitin-protein ligase that promotes SOCS-1 proteasomal degradation. As a widely expressed homodimer, TRIM8 localizes to nuclear bodies and contains two B box-type zinc fingers and one RING-type zinc finger. TRIM8 is expressed in lung, heart, brain and skeletal muscle, with low levels detected in intestine, placenta, leukocytes and liver. The gene encoding TRIM8 maps to human chromosome 10q24.32.