GRHL3 is a transcription factor that binds the consensus DNA sequence 5'-AACCGGTT-3' to function as both an activator and repressor of target genes 12. In normal physiology, GRHL3 is essential for epidermal barrier formation and neural tube closure, with functional redundancy with GRHL2 in epidermal wound repair 3. GRHL3 expression is induced during epidermal differentiation through glucose-dependent mechanisms involving the IRF6 transcription factor 4 and DDX21-mediated mRNA splicing 5, where it activates pro-differentiation genes including TGM3. In disease contexts, GRHL3 plays complex and sometimes contradictory roles. In cancer, GRHL3 overexpression promotes epithelial-mesenchymal transition and invasion through E-cadherin repression in colorectal and breast cancers 67, and mediates hepatocellular carcinoma metastasis via the GPX4/PTEN/PI3K/AKT axis 8. Conversely, GRHL3 restricts APOBEC3A expression to differentiated cells, preventing mutagenic activity during DNA replication, though this restriction is lost in squamous cell carcinoma 9. GRHL3 also supports triple-negative breast cancer angiogenesis through HIF1A/VEGFA signaling 10 and may inhibit T cell-mediated anti-tumor immunity by regulating RNF114 11. These findings underscore GRHL3's context-dependent roles in development, homeostasis, and malignancy.