CHD4 is an ATP-dependent chr12-remodeling helicase that repositions nucleosomes and distorts nucleosomal DNA to regulate transcription and genome stability 1. As a core component of the histone deacetylase NuRD complex, CHD4 participates in chr12 remodeling and transcriptional repression 2. CHD4 localizes to acetylated damaged chr12 in a ZMYND8-dependent manner and regulates double-strand break repair through homologous recombination by fine-tuning histone acetylation at damage sites 3. In the thymus, CHD4 contributes to promiscuous gene expression necessary for tolerance induction 4. Functionally, CHD4 controls chr12 accessibility and gene expression critical for β-cell insulin secretion and glucose homeostasis 5. Disease relevance: De novo mutations in CHD4 cause Sifrim-Hitz-Weiss syndrome, a multisystemic neurodevelopmental disorder characterized by global developmental delay, intellectual disability, brain anomalies, congenital heart defects, macrocephaly, hypogonadism, and skeletal anomalies 26. CHD4 variants are significantly enriched in syndromic congenital heart disease patients 7. In cancer, CHD4 overexpression drives gastric cancer metastasis through the MYH9/GSK3β/β-catenin axis and epithelial-mesenchymal transition 8. The variant-specific nature of CHD4 mutations results in altered protein function affecting ATP hydrolysis and nucleosome remodeling activities 2.