C-X-C motif chemokine receptor 2 (CXCR2), encoded by the CXCR2 gene, is a member of the G protein-coupled receptor family ^[1]. While predominantly expressed in neutrophils, CXCR2 is also found in diverse tissue cells, including brain, lung, and other immune cell types ^[1-2]. As a cell surface receptor, CXCR2 binds specific chemokines, such as interleukin-8 (IL-8) and CXCL1, initiating intracellular signaling cascades involving phosphatidylinositol-3 kinase (PI3K), mitogen-activated protein kinase (MAPK), and nuclear factor-κB (NF-κB) pathways ^[2]. The principal physiological role of CXCR2 is to mediate neutrophil chemotaxis to sites of inflammation, thereby contributing to immune responses and inflammatory processes ^[3]. Additionally, CXCR2 has been implicated in the development and progression of various cancers, including melanoma, pancreatic, ovarian, breast, and prostate cancers, by regulating tumor cell survival, proliferation, metastasis, and angiogenesis ^[1-4]. Aberrant CXCR2 expression or function is associated with a range of pathological conditions, encompassing both inflammatory diseases and cancers. The B6-hCXCR2 mouse is a humanized model constructed using gene editing technology to replace the entire base sequence of the mouse Cxcr2 gene in situ with the corresponding sequence from the human CXCR2 gene. Homozygous B6-hCXCR2 mice are viable and fertile. This model can be used for studying the pathological mechanisms and therapeutic approaches of inflammatory diseases and cancers, and for the development of CXCR2-targeted drugs.

Vmn1r234 is located on chromosome 17 of mice. SgRNA and ssDNA will be designed using Nuclease Technology; Vmn1r234 conditional knockout mice will be obtained by high-throughput electroporation of fertilized eggs. After sexual maturity, sperm will be collected for cryopreservation.