BHLHE22 belongs to the basic helix-loop-helix (bHLH) family of transcription factors that regulate cell fate determination, proliferation, and differentiation. These proteins function as dimers and bind to an E-box DNA sequence (CANNTG). BHLHE22 is expressed exclusively in the central nervous system and retina (Xu et al., 2002 [PubMed 12213201]).[supplied by OMIM, Jul 2010]