Kruppel-like zinc finger proteins such as ZNF189 contain a conserved stretch of 7 amino acids that connects a variable number of DNA-binding zinc finger repeats of the cys(2)his(2) (C2H2) type (summarized by Odeberg et al., 1998 [PubMed 9653648]). Approximately 30% of human Kruppel-like zinc finger proteins contain an N-terminal Kruppel-associated box (KRAB) domain. The KRAB domain consists of approximately 75 amino acids that may be subdivided into an A box, which is present in every KRAB domain and is essential for transcriptional repression, and a B box, which is not always present.[supplied by OMIM, May 2010].