HOXD4 is a sequence-specific transcription factor that regulates anterior-posterior pattern specification during embryonic development 1. It functions as a DNA-binding transcriptional activator, controlling expression through interaction with retinoid-responsive enhancer elements and retinoic acid receptors 12. During early embryogenesis, HOXD4 is activated in a temporal and spatially restricted manner, with retinoic acid serving as a critical developmental regulator 23. The gene directs proper expression in the neural tube and paraxial mesoderm, establishing correct anterior boundaries in the hindbrain up to rhombomere 6/7 3. In disease contexts, HOXD4 overexpression drives tumorigenesis across multiple cancer types. In glioblastoma, HOXD4 activates ESM1 transcription to promote cell proliferation, invasion, migration, and angiogenesis 4. Similarly, elevated HOXD4 expression correlates with poor prognosis in ovarian serous carcinoma and gastric adenocarcinoma, promoting cell proliferation through c-Myc and cyclin D1 upregulation 56. Conversely, HOXD4 loss-of-function mutations cause spinal extradural arachnoid cyst through haplo-insufficiency, indicating HOXD4's essential role in dura mater development 7. Across pan-cancer analysis, HOXD4 downregulation is associated with improved survival outcomes in renal cell carcinoma and other malignancies 8.