There are 54 identified members of the human ZSCAN transcription factor family, and because they are all zinc finger proteins, they are referred to as ZNF proteins. ZSCAN transcription factors contain two main domains, the zinc finger domain and the SCAN box. The zinc finger domain in the ZSCAN transcription factor contains a C2H2 motif. The C-terminus of the ZSCAN transcription factor contains three or more fingers consisting of two conserved cysteine residues and two histidine residues coordinated with a zinc ion. The C2H2 ZNF transcription factors are the main type of ZNF transcription factors. The highly conserved SCAN domain consists of 84 amino acids rich in leucine residues; therefore, this domain is also known as the leucine-rich region (LeR). The SCAN domain has an amphipathic secondary structure and is involved in protein-protein interactions, in particular for self-association and to mediate oligomerization.