Asxl1, or Additional sex combs-like 1, is a chromatin regulator gene belonging to a family of three genes homologous to the Drosophila Asx gene. It is located near the DNMT3B gene, contains 14 exons, and is expressed in most hematopoietic cell types. Asxl1 assembles chromatin modification complexes and transcription factors as an Enhancer of Trithorax and Polycomb (ETP) protein, regulating gene expression crucial for stem cell functions in hematopoiesis [1].

Deletion of Asxl1 in mice alters histone modifications, including H3K4me3, H3K27me3, and H2AK119Ub, and facilitates aberrant gene expression, resulting in myeloid transformation. However, these mice also exhibit impaired hematopoietic stem cell (HSC) function. This shows that Asxl1 plays a role in normal hematopoiesis, and its deletion can lead to myeloid malignancies [2].

In conclusion, Asxl1 is essential for normal hematopoiesis through its role in histone modifications and gene expression regulation. Mouse models with Asxl1 deletion have revealed its significance in maintaining HSC function and the development of myeloid malignancies. Understanding Asxl1's function provides insights into the mechanisms of hematopoietic diseases, potentially leading to new therapeutic strategies for myeloid malignancies.