The article discusses the role of epigenetic regulatory layers in the 3D nucleus, focusing on how gene regulation is influenced by the structure and organization of the genome. It reviews recent advances in genome biology, highlighting the complex interplay between DNA, RNA, and proteins in regulating gene expression. The central dogma of molecular biology, introduced by Francis Crick, outlines the directionality of sequence information transfer from DNA to RNA and proteins. However, the mechanisms underlying gene regulation remain complex, involving the activity of nuclear factors and the three-dimensional organization of the genome. The article explores how regulatory DNA elements, such as cis-regulatory elements (CREs), and non-coding RNAs (ncRNAs) contribute to gene regulation. It discusses the discovery of topologically associating domains (TADs), which are genomic regions with preferred local chromatin interactions. TADs are flanked by boundary regions enriched for transcription factors and cohesin binding. The study also examines the spatial organization of the genome, including the roles of heterochromatin and euchromatin, and how these structures influence gene expression. The article highlights the importance of chromatin structure and the dynamic interactions between DNA, RNA, and proteins in regulating gene expression. It discusses the role of phase separation in forming heterochromatin and the involvement of Polycomb repressive complexes in gene regulation. The study also addresses the spatial positioning of genes within chromosome territories and how this relates to gene expression. The article emphasizes the need for further research to understand the complex interactions between genome structure and gene regulation, particularly in the context of disease and development. It discusses the use of multimodal technologies to study genome organization and the potential of integrating data from different experimental approaches to gain a comprehensive understanding of genome function. The study concludes that understanding the molecular mechanisms underlying gene regulation is crucial for advancing our knowledge of cellular processes and developing new therapeutic strategies.The article discusses the role of epigenetic regulatory layers in the 3D nucleus, focusing on how gene regulation is influenced by the structure and organization of the genome. It reviews recent advances in genome biology, highlighting the complex interplay between DNA, RNA, and proteins in regulating gene expression. The central dogma of molecular biology, introduced by Francis Crick, outlines the directionality of sequence information transfer from DNA to RNA and proteins. However, the mechanisms underlying gene regulation remain complex, involving the activity of nuclear factors and the three-dimensional organization of the genome. The article explores how regulatory DNA elements, such as cis-regulatory elements (CREs), and non-coding RNAs (ncRNAs) contribute to gene regulation. It discusses the discovery of topologically associating domains (TADs), which are genomic regions with preferred local chromatin interactions. TADs are flanked by boundary regions enriched for transcription factors and cohesin binding. The study also examines the spatial organization of the genome, including the roles of heterochromatin and euchromatin, and how these structures influence gene expression. The article highlights the importance of chromatin structure and the dynamic interactions between DNA, RNA, and proteins in regulating gene expression. It discusses the role of phase separation in forming heterochromatin and the involvement of Polycomb repressive complexes in gene regulation. The study also addresses the spatial positioning of genes within chromosome territories and how this relates to gene expression. The article emphasizes the need for further research to understand the complex interactions between genome structure and gene regulation, particularly in the context of disease and development. It discusses the use of multimodal technologies to study genome organization and the potential of integrating data from different experimental approaches to gain a comprehensive understanding of genome function. The study concludes that understanding the molecular mechanisms underlying gene regulation is crucial for advancing our knowledge of cellular processes and developing new therapeutic strategies.