TCF12, also known as HTF4, is a member of the basic helix-loop-helix (bHLH) E-protein family that recognizes the consensus binding site (E-box) CANNTG. TCF12 is expressed in many tissues, among them skeletal muscle, thymus, B- and T-cells, and may participate in regulating lineage-specific gene expression through the formation of heterodimers with other bHLH E-proteins. TCF12, in combination with E2A, is required to block thymocyte proliferation prior to pre-TCR expression and is critical for proper T cell differentiation. Recent reports have shown that TCF12 is also a critical factor required for the development of invariant natural killer T cells.Synonyms: DNA-binding protein HTF4, E-box-binding protein, HEB, HTF-4, HTF4, Transcription factor 12, Transcription factor HTF-4