HDAC2, histone deacetylase 2, is a key epigenetic regulator present in the nucleus. It deacetylates histones H3 and H4, modifying chromatin structures, and functions as a transcriptional regulator to control the expression of various genes. This process is crucial for normal cellular function and is involved in multiple pathways. HDAC2 has been implicated in various biological processes and diseases, making it an important target for research, and genetic models are valuable tools in studying its functions [1].

In colorectal cancer, HDAC2 deletion or knockdown induced epithelial mesenchymal transition (EMT) and metastasis by upregulating the long noncoding RNA H19, suggesting it acts as a metastasis suppressor [2]. In clear cell renal cell carcinoma (ccRCC), HDAC2 inhibitors resensitize ccRCC to tyrosine kinase inhibitors through the YY1/HDAC2 complex [3]. Inhibition of HDAC2 in colorectal cancer promotes NLRP3/GSDMD-mediated pyroptosis, enhancing antitumour therapy [4]. In hepatocellular carcinoma (HCC), HDAC2 promotes autophagy-associated malignant progression by transcriptionally activating LAPTM4B, and its inhibitor alleviates HCC malignant development [5]. In pancreatic ductal adenocarcinoma (PDAC), HDAC2 controls cell cycle in vitro and metastasis in vivo, especially in undifferentiated, mesenchymal PDAC cells [6].

In conclusion, HDAC2 plays essential roles in multiple biological processes, especially in cancer-related pathways such as metastasis, autophagy, and response to therapy. Gene knockout or knockdown studies in mouse models for HDAC2 have been instrumental in revealing its functions in various disease areas, mainly different types of cancers, providing potential therapeutic targets for these diseases.