MTA3 (metastasis associated 1 family member 3) functions as a component of the nucleosome remodeling and deacetylase (NuRD) complex, participating in chr2 remodeling and transcriptional regulation 12. The protein acts as both a transcriptional corepressor and coactivator, modulating epigenetic modifications to regulate cell differentiation, apoptosis, and metabolism 2. MTA3 plays a crucial role in maintaining epithelial architecture by repressing SNAI1 transcription, thereby regulating E-cadherin levels and inhibiting epithelial-mesenchymal transition 1. In stem cell biology, MTA3 is essential for maintaining embryonic stem cell pluripotency, as its knockdown induces mesendoderm differentiation 3. The protein exhibits context-dependent roles in cancer, functioning as a tumor suppressor in some contexts by down-regulating Snail and repressing cancer cell invasion and migration 1, while acting as an oncogene in others, such as hepatocellular carcinoma where overexpression correlates with poor prognosis 4. MTA3 also regulates steroidogenesis in Leydig cells, where oxidative stress in type 2 diabetes mellitus suppresses its expression through NR4A1-mediated mechanisms 5. Additionally, MTA3 participates in hypoxia responses by regulating HIF1α expression in trophoblasts 6.