Inhibitor of DNA Binding 2 （ID2） is a part of the inhibitor of DNA binding family， whose members are transcriptional regulators that contain a helix-loop-helix （HLH） domain but not a basic domain. Members of the ID family inhibit the functions of basic helix-loop-helix transcription factors in a dominant-negative way by suppressing their heterodimerization partners through the HLH domains. ID2 play a role in negatively regulating cell differentiation and may be an inhibitor of tissue-specific gene expression.
