Tripartite motif-containing protein 38 (TRIM38), also known as RING finger protein 15 (RNF15) or zinc finger protein RoRet, is a 465 amino acid member of the TRIM family, also known as the RING-B-box coiled-coil (RBCC) family. Members of the RBCC family have an N-terminal RING finger, followed by one or two zinc-binding domains (B-box domains), a leucine coiled-coil region and a variable C-terminal domain. Found in all eukaryotes, members of the RBCC family typically function within a larger protein complex and possess ubiquitin-protein isopeptide ligase activity.