The TNFRSF13B gene encodes the transmembrane activator and CAML interactor (TACI), a receptor belonging to the tumor necrosis factor receptor superfamily, predominantly expressed on B lymphocytes. TACI plays a critical role in humoral immunity by recognizing the TNF ligands B cell-activating factor (BAFF) and a proliferation-inducing ligand (APRIL) ^[1]. Upon ligand binding, TACI modulates intracellular signaling pathways, including NFAT, AP1, and NF-κB, which are essential for B cell survival, maturation into plasma cells, and the production of immunoglobulins ^[2]. Notably, TNFRSF13B is highly polymorphic, and specific genetic variants are strongly associated with the pathogenesis of common variable immunodeficiency (CVID), a primary immunodeficiency characterized by hypogammaglobulinemia and increased susceptibility to infection ^[3]. While the precise mechanisms by which these variants contribute to disease are still under investigation, they often result in impaired TACI function, disrupting normal B cell development and antibody responses ^[4]. Further research into the regulation and function of TACI is crucial for understanding the complex etiology of CVID and for developing targeted therapeutic strategies for this and potentially other immune-related disorders. The hTACI(TNFRSF13B) mouse is a humanized model constructed by replacing the exon 2 plus partial intron 2 of the mouse Tnfrsf13b gene in situ with the Kozak-TNFRSF13B chimeric CDS-3'UTR of mouse Tnfrsf13b-WPRE-BGH pA cassette. The hTACI(TNFRSF13B) mice can be used for studies on common variable immunodeficiency (CVID), and pathogenesis of immune-related diseases, as well as for TNFRSF13B-targeted drug development.