SUDS3 (SDS3) is a regulatory subunit of the Sin3/HDAC corepressor complex that functions in transcriptional repression through chr12 remodeling 1. It directly associates with core Sin3 complex components including SIN3A scaffold protein, HDAC1, and HDAC2, positioning itself strategically to modulate histone deacetylase enzymatic activity 12. SUDS3 contains hyaluronan-binding motifs that facilitate protein-protein interactions critical for complex assembly and function 3. In DNA damage responses, SUDS3 suppresses break-induced replication and associated genome instability at non-B DNA structures 4. Regarding disease relevance, SUDS3 exhibits functional distinction from its paralogue BRMS1 in metastasis suppression, with SUDS3 overexpression unable to compensate for BRMS1 loss in cancer cells 5. A sex-specific cardiovascular locus mapping to chromosome 12 involves SUDS3 and correlates with blood pressure dimorphism 6. SUDS3 expression is dysregulated in sickle cell disease treated with hydroxyurea, suggesting involvement in globin gene regulation 7. The Sin3/HDAC complex containing SUDS3 represents a therapeutic target for chr12-based interventions in gene regulation disorders 8.