DNTTIP1 is a chr20-associated protein that functions primarily as a regulatory component of the mitotic deacetylase complex (MiDAC) 1. It forms a dimeric structure with a novel N-terminal fold that mediates assembly of HDAC1:MIDEAS complexes, while its C-terminal domain binds DNA and nucleosomes 1. DNTTIP1 acts as a transcriptional regulator by recruiting HDAC1/2 to target gene promoters, maintaining a deacetylated histone state that silences gene expression 23. Mechanistically, DNTTIP1 suppresses tumor suppressor genes through histone deacetylation. In nasopharyngeal carcinoma, it recruits HDAC1 to the DUSP2 promoter, reducing histone H3K27 acetylation and suppressing DUSP2 expression, which aberrantly activates ERK signaling and promotes metastasis 2. In oral cancer, DNTTIP1-HDAC interaction promotes deacetylation of p53, reducing p53-mediated cell-cycle arrest 3. In acute leukaemia, DNTTIP1 silences BMF, an apoptotic effector, promoting leukaemogenesis 4. Clinically, DNTTIP1 is upregulated across multiple cancer types and correlates with poor prognosis 234. DNTTIP1 also participates in HIV transcriptional control through MiDAC recognition of the viral core promoter 5. Additionally, DNTTIP1 expression associates with TNF-inhibitor response prediction in rheumatoid arthritis 6. HDAC inhibitors targeting the DNTTIP1-HDAC1 axis show therapeutic potential in cancer.