HOXD8 is a sequence-specific transcription factor that plays crucial roles in developmental regulation and cancer biology. As part of the homeobox gene family, HOXD8 provides cells with positional identities along the anterior-posterior axis during embryonic development 1. In neuroblastoma cells, HOXD8 expression is upregulated during chemical-induced differentiation with retinoic acid and dibutyryl cyclic AMP, suggesting its involvement in neuronal maturation 1. The gene exhibits complex expression patterns across different cancer types. In gliomas, HOXD8 is significantly upregulated and promotes tumor progression by regulating epithelial-mesenchymal transition (EMT), enhancing cell proliferation, migration, and invasion 2. Conversely, in triple-negative breast cancer, HOXD8 functions as a tumor suppressor, with reduced expression associated with cancer progression and its overexpression inhibiting cell growth through AKT/mTOR pathway suppression 3. HOXD8 also participates in epigenetic regulation networks, collaborating with long non-coding RNAs like DIAPH2-AS1 to control gene expression in placental cells 4. Additionally, hypermethylation of HOXD8 serves as a highly specific biomarker for biliary tract cancers, detectable in both tissue and bile samples with 100% sensitivity and specificity 5.