Forkhead box D3also known asFOXD3is aforkhead proteinthat in humans is encoded by theFOXD3gene. This gene belongs to the forkhead protein family of transcription factorss which is characterized by a DNA-binding forkhead domain. FoxD3 functions as a transcriptional repressor and contains the C-terminal engrailed homology-1 motif (eh1), which provides an interactive surface with a transcriptional co-repressor Grg4 (Groucho-related gene-4).