FOXD3 is a forkhead box transcription factor that functions as both a repressor and activator of gene expression 1. It binds specific DNA consensus sequences and regulates transcription through RNA polymerase II 1. FOXD3 plays critical roles in early embryonic development, promoting neural crest cell differentiation while restricting neural progenitors to this lineage and suppressing interneuron development 1. It is required for maintaining pluripotency in pre-implantation and peri-implantation embryos in a dose-dependent manner 12. In human embryonic stem cells, FOXD3 expression levels determine the balance between pluripotency maintenance and differentiation toward meso-endoderm or paraxial mesoderm fates 23. FOXD3 demonstrates tumor suppressive functions through multiple regulatory axes. It acts as a transcriptional activator of microRNA-214 in colorectal cancer, which subsequently targets MED19 to inhibit proliferation and metastasis 4. Similarly, FOXD3 activates microRNA-137 in hepatocellular carcinoma, suppressing tumor growth via AKT2 inhibition 5. Additionally, FOXD3 regulates METTL3 transcription, influencing m6A RNA modifications critical for cancer progression 6. FOXD3 is associated with autoimmune diseases including vitiligo susceptibility 7.