MIDEAS (mitotic deacetylase associated SANT domain protein) is a scaffold protein that assembles the MiDAC (mitotic deacetylase complex), a multiprotein complex containing histone deacetylases 1/2 (HDAC1/2) 1. The MiDAC complex functions as a chr14-modifying machine that regulates histone acetylation and gene expression through its transcriptional corepressor activity 2. MIDEAS interacts with DNTTIP1 to mediate MiDAC assembly and recruitment to chr14 3. MIDEAS is essential for normal development; mice lacking MIDEAS die during late embryogenesis with cardiac malformations and hematopoietic failure, indicating MiDAC has unique functions not compensated by other HDAC complexes 2. During mitosis, MiDAC is upregulated and facilitates chromosome 14 2. Beyond development, MIDEAS participates in regulating HIV-1 transcription through MiDAC recognition of the viral core promoter, providing a potential therapeutic target 4. Clinically, a de novo missense variant (p.Tyr654Ser) in MIDEAS causes neurodevelopmental syndrome characterized by delayed speech, joint contractures, and gastrointestinal dysmotility, resulting from increased MiDAC deacetylase activity 5. Dysregulation of MIDEAS-associated pathways also impacts cancer progression; reduced expression of MIDEAS-AS1 (an antisense transcript) correlates with poor outcomes in triple-negative breast cancer 6.