Zinc-finger proteins contain DNA-binding domains and have a wide variety of functions, most of which encompass some form of transcriptional activation or repression. The majority of zinc-finger proteins contain a Kr¨1ppel-type DNA binding domain and a KRAB domain, which is thought to interact with KAP1, thereby recruiting histone modifying proteins. Zinc finger and BTB domain-containing protein 44 (ZBTB44), also known as BTBD15, is a 570 amino acid member of the Kr¨1ppel C2H2-type zinc-finger protein family. Localized to the nucleus, ZBTB44 contains a BTB domain, also known as a POZ domain, which inhibits DNA binding and mediates homotypic and heterotypic dimerization. Characteristics of the BTB domain suggest that ZBTB44 functions as a transcription regulator. Four isoforms of ZBTB44 have been identified.