A portion of amino acids 9-38 from the human protein was used as the immunogen for this HES1 antibody.
HES1 belongs to the basic helix-loop-helix family of transcription factors. It is a transcriptional repressor of genes that require a bHLH protein for their transcription. HES1 has a particular type of basic domain that contains a helix interrupting protein that binds to the N-box rather than the canonical E-box.