The ITGA4 gene encodes the integrin α4 subunit, which pairs with the integrin β7 subunit, encoded by the ITGB7 gene, to form the heterodimeric transmembrane protein α4β7, a key member of the integrin protein family ^[1]. α4β7 is prominently expressed in immune tissues, including lymph nodes, bone marrow, spleen, and blood, as well as in diverse immune cell populations, such as T lymphocytes, B lymphocytes, monocytes, granulocytes, and natural killer cells ^[1]. Functionally, α4β7 mediates cell adhesion and migration, critically regulating immune cell trafficking and inflammatory processes. Specifically, α4β7 facilitates lymphocyte migration to sites of inflammation and intestinal lymphoid tissues through interactions with vascular cell adhesion molecule-1 (VCAM-1) and mucosal addressin cell adhesion molecule-1 (MAdCAM-1) ^[2]. Notably, ITGA4 and ITGB7 have been implicated in the pathogenesis of autoimmune diseases, including inflammatory bowel disease (IBD), Crohn's disease, ulcerative colitis, and multiple sclerosis ^[2-4]. Consequently, the targeting of α4β7 has emerged as a key therapeutic strategy for inflammatory and autoimmune disorders. TNF-like ligand 1A (TL1A), also known as TNF superfamily member 15 (TNFSF15), is a member of the tumor necrosis factor (TNF) family encoded by the TNFSF15 gene in humans. TL1A acts as a ligand for death receptor 3 (DR3) and decoy receptor 3 (DcR3), providing a stimulatory signal for downstream pathways. It regulates the proliferation, activation, and apoptosis of effector cells, as well as cytokine and chemokine production. TL1A is expressed in various immune cells, including monocytes, macrophages, dendritic cells, and T cells, as well as in non-immune cells such as synovial fibroblasts and endothelial cells. It plays a crucial role in modulating immune responses by promoting the differentiation and survival of T cells, particularly Th17 cells involved in inflammatory processes ^[5]. TL1A enhances IL-2 responses in anti-CD3/CD28-stimulated T cells and synergizes with IL-12 and IL-18 to augment IFN-γ release in human T and NK cells, biasing T cell differentiation toward a Th1 phenotype ^[6]. Dysregulation of TL1A expression is implicated in autoimmune diseases, including inflammatory bowel disease (IBD), rheumatoid arthritis (RA), primary biliary cholangitis (PBC), systemic lupus erythematosus (SLE), and ankylosing spondylitis (AS) ^[5]. TL1A has emerged as a promising therapeutic target, with ongoing research focused on developing monoclonal antibodies and other biologics to neutralize TL1A and reduce inflammation in autoimmune disorders. Clinical trial results suggest that TL1A inhibition can be used in the treatment of various autoimmune diseases, particularly IBD ^[7-9]. B6-hα4β7/hTL1A mouse is a triple-gene humanized model for ITGA4, ITGB7, and TNFSF15, generated by crossing B6-hα4β7 mice with B6-hTL1A (TNFSF15) mice (Catalog No.: C001603). This model serves as a valuable tool for researching immune-related diseases, applicable to studies on T cell differentiation and survival, immune response regulation, and autoimmune diseases. It provides a robust preclinical research platform for the screening, development, and safety evaluation of α4β7/TL1A-targeted drugs.

Lipoprotein(a) (LP(a)) is considered one of the risk factors for atherosclerosis, coronary heart disease, stroke, and other cardiovascular diseases (CVD) ^[1]. It is similar in size and lipid content to low-density lipoprotein (LDL) and contains the lipoprotein ApoB-100, but also includes a variable-length lipoprotein(a) (Apo(a)), which is covalently bound to ApoB-100 via a single disulfide bond. LP(a) plays an important role in systemic lipid transport, guiding inflammatory cells into the vascular wall and causing smooth muscle cell proliferation. In addition, it is also involved in wound healing and tissue repair, interacting with components of the vascular wall and extracellular matrix ^[2]. LP(a) can also cause arterial narrowing by attaching to the arterial wall, accelerating the formation of blood clots, and leading to a series of pathological changes ^[3]. The plasma concentration of LP(a) is closely related to genetic factors and is mainly regulated by the LPA gene. Therefore, the LPA gene is an important potential target for treating cardiovascular disease. The LPA gene is expressed in humans and non-human primates but not mice. By crossing mice conditional expression of human LPA (LSL-hLPA) with liver-specific Cre expression mice (Alb-Cre) that specifically overexpress the human LPA gene in the liver can be obtained. ApoB is a protein that plays a central role in lipid metabolism and cardiovascular disease (CVD) and is responsible for transporting cholesterol and other fat molecules to all tissues throughout the body ^[4]. The accumulation of cholesterol and other lipids can promote the formation of arterial plaques, leading to arterial narrowing and reduced blood flow, increasing the risk of cardiovascular events such as myocardial infarction and stroke ^[5]. Therefore, high levels of ApoB are a major risk factor for plaque in cardiovascular diseases such as atherosclerosis. ApoB100 is the most abundant subtype of ApoB in humans and the most important subtype of ApoB in cardiovascular disease (CVD) ^[6]. Mice overexpressing the human APOB gene have significantly elevated LDL cholesterol in serum. The B6-RCL-hLPA/Alb-cre/TG(APOB) mice express human LP(a) and ApoB, two risk factors for cardiovascular disease. It can be used in the study of hyperlipidemia, stroke, coronary heart disease, familial hypercholesterolemia (FH), and other atherosclerotic cardiovascular diseases (ASCVD). Internal data (not shown) indicates that, compared to the Cyagen strain B6-LPA(CKI)/Alb-Cre&Tg(APOB) mice (Catalog No. C001494), this model exhibits a more stable expression of human LPA protein at different ages. Please choose the model based on the experimental need for continuous stability of human LPA protein expression.

Complement component C3 plays a central role in activating the complement system and is the most abundant complement protein in human plasma, primarily synthesized in the liver. As part of the innate immune system, the complement system is activated during tissue damage and pathogen invasion, playing a crucial role in the inflammatory response, host homeostasis, and pathogen defense. The complement cascade is activated through the classical pathway, alternative pathway, and lectin pathway, all of which generate C3 convertase, which cleaves C3 into C3a and C3b. C3a is a potent anaphylatoxin with pro-inflammatory activity, while C3b is a regulator that induces C5 cleavage, thereby participating in the dissolution and clearance of immune complexes. Mutations in this gene are associated with atypical hemolytic uremic syndrome (aHUS) and age-related macular degeneration (AMD). Deficiencies in C3 and C3-derived peptides can lead to autoimmune diseases (such as rheumatoid arthritis, systemic lupus erythematosus, and vasculitis) and make individuals susceptible to recurrent respiratory infections and infections caused by encapsulated organisms. Conversely, excessive activation of C3 and related complement components is associated with kidney diseases (immune complex glomerulonephritis, hemolytic uremic syndrome, lupus nephritis, membranous nephropathy, and immune-mediated nephropathy) ^[1-2]. The Transferrin receptor (TFRC) gene encodes Transferrin Receptor 1 (TFR1), a protein that is expressed at low levels in most normal cells but shows increased expression in highly proliferative cells, such as basal epidermal cells, intestinal epithelium, and certain activated immune cells. Brain capillary endothelial cells, which constitute the blood-brain barrier (BBB), also express this receptor at high levels ^[3]. TFR1 plays a critical role in maintaining iron metabolism and homeostasis by facilitating receptor-mediated endocytosis of iron-bound transferrin (Tf) via Tf cycling, thereby promoting iron uptake ^[4]. Cellular iron deficiency can lead to apoptosis, while cellular transformation requires substantial iron to sustain proliferation, with iron overload contributing to tumor progression. The high expression of TFR1 in many tumors makes it a potential tumor marker, offering a target for therapies to inhibit tumor growth and metastasis ^[3]. Moreover, TFR1 is implicated in anemia and iron metabolism disorders. Studies have shown that elevated TFR1 expression in cardiomyocytes is associated with exacerbated inflammation in myocarditis patients ^[5]. Various clinical drugs targeting TFR1 are currently under development, including antisense oligonucleotides (ASOs), antibody-drug conjugates (ADCs), and antibody-oligonucleotide conjugates, applicable to diseases such as cancer, anemia, and neurodegenerative disorders. Research indicates that enhancing antibody transport across the blood-brain barrier via TFR1, by forming specific bispecific antibodies with anti-β-amyloid antibodies, can improve therapeutic outcomes in Alzheimer's patients ^[6-7]. As research progresses, TFR1 is expected to become an effective clinical target for multiple diseases and a synergistic target for drug delivery across the blood-brain barrier (BBB). The B6-hC3/hTFRC(CDS) mouse model is a humanized model obtained by breeding huC3 mice (Catalog No.: C001955) with B6-hTFRC(CDS) mice (Catalog No.: C001584). This model can be used for research on complement-mediated diseases, iron metabolism disorders, neurodegenerative diseases, and tumor development, aiding in studying C3/TFRC-targeted drugs.

The IL23A gene encodes the p19 subunit, a component of interleukin-23 (IL-23), which forms a heterodimer with the p40 subunit (encoded by IL12B) to generate the functional IL-23 cytokine ^[1]. Primarily expressed by activated dendritic cells, macrophages, and monocytes, IL-23 signals through the IL-23 receptor (IL-23R) complex, activating the JAK-STAT pathway to promote Th17 cell differentiation and maintain IL-17 production. This process drives inflammatory responses and mucosal immunity against extracellular pathogens ^[1-2]. . Genetic polymorphisms within IL23A are strongly associated with autoimmune and inflammatory diseases, including psoriasis, Crohn's disease, and inflammatory bowel disease, due to dysregulated Th17 activity and chronic inflammation ^[1-2]. Monoclonal antibodies targeting IL-23, such as risankizumab and guselkumab, selectively block the p19 subunit, demonstrating therapeutic efficacy in psoriasis and inflammatory bowel diseases by suppressing pathogenic IL-17/Th17 pathways ^[3]. Also, monoclonal antibodies targeting IL-12B, such as ustekinumab, are clinically utilized for the treatment of moderate to severe psoriasis and Crohn's disease ^[4]. While IL-23 plays a role in protective immunity, its overactivation contributes to tissue damage in autoimmune settings, highlighting its dual function in immune regulation and disease pathogenesis ^[1-5]. TNF-like ligand 1A (TL1A), also known as TNF superfamily member 15 (TNFSF15), is a member of the tumor necrosis factor (TNF) family encoded by the TNFSF15 gene in humans. TL1A acts as a ligand for death receptor 3 (DR3) and decoy receptor 3 (DcR3), providing a stimulatory signal for downstream pathways. It regulates the proliferation, activation, and apoptosis of effector cells, as well as cytokine and chemokine production. TL1A is expressed in various immune cells, including monocytes, macrophages, dendritic cells, and T cells, as well as in non-immune cells such as synovial fibroblasts and endothelial cells. It plays a crucial role in modulating immune responses by promoting the differentiation and survival of T cells, particularly Th17 cells involved in inflammatory processes ^[6]. TL1A enhances IL-2 responses in anti-CD3/CD28-stimulated T cells and synergizes with IL-12 and IL-18 to augment IFN-γ release in human T and NK cells, biasing T cell differentiation toward a Th1 phenotype ^[7]. Dysregulation of TL1A expression is implicated in autoimmune diseases, including inflammatory bowel disease (IBD), rheumatoid arthritis (RA), primary biliary cholangitis (PBC), systemic lupus erythematosus (SLE), and ankylosing spondylitis (AS) ^[6]. TL1A has emerged as a promising therapeutic target, with ongoing research focused on developing monoclonal antibodies and other biologics to neutralize TL1A and reduce inflammation in autoimmune disorders. Clinical trial results suggest that TL1A inhibition can be used in the treatment of various autoimmune diseases, particularly IBD ^[8-10]. B6-hIL23A/hIL12B/hTL1A mouse is a triple-gene humanized model for IL23A, IL12B, and TNFSF15, generated by crossing B6-hIL23A&hIL12B mice (Catalog No.: C001620) with B6-hTL1A (TNFSF15) mice (Catalog No.: C001603). This model serves as a valuable tool for researching immune-related diseases, applicable to studies on immune response regulation and autoimmune diseases. It provides a robust preclinical research platform for the screening, development, and safety evaluation of drugs targeting IL23A/IL12B/TL1A.

Interleukin 17A (IL-17A) is a signature cytokine of the T helper 17 (Th17) subset of CD4+ T cells and one of the six members (IL-17A~IL-17F) of the IL-17 family. IL-17A is primarily produced by Th17 cells and can also be produced by other immune cells under certain conditions, including CD8+ T cells, γδT cells, natural killer T (NKT) cells, monocytes, neutrophils, and microglia ^[1]. IL-17A mediates downstream pathways that induce the production of inflammatory molecules, chemokines, antimicrobial peptides, and remodeling proteins, which have important effects on host defense, cell transport, immune regulation, and tissue repair, especially in inducing innate immune defense. In healthy skin, commensal microorganisms induce the production of IL-17A to provide antifungal protection. When the skin barrier is damaged, IL-17A promotes epithelial cell proliferation and can clear pathogenic factors, promoting tissue repair and wound healing ^[2]. IL-17A usually protects the body when it is acutely injured, but when a wound requires long-term healing and becomes a chronic injury, the role of IL-17A may transform into wound erosion or excessive proliferation, ultimately leading to loss of function ^[3]. IL-17A plays a key role in various infectious diseases, inflammations, autoimmune diseases, and cancers. Its high expression level is associated with chronic inflammatory diseases such as rheumatoid arthritis, psoriasis, and multiple sclerosis. Lung injury caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is largely the result of the promotion of inflammatory reactions by cytokines such as IL-17A. Dysregulation of IL-17 signaling promotes pathogenic inflammation. IL-17A has a pathogenic role in mediating the important inflammatory pathway of psoriasis. The IL-23/Th17/IL-17A pathway is a key link in its pathogenesis, and inhibiting the expression of IL-17A can effectively alleviate psoriasis ^[4]. IL-17A is also associated with the course of ankylosing spondylitis (AS), and IL-17A inhibitors can effectively treat AS ^[5]. In addition, studies have shown that IL-17A is involved in the pathogenesis of neurodegenerative diseases in the central nervous system, and its expression level is related to the severity and progression of the disease ^[3]. The IL17F gene, located on chromosome 6p12.2, is primarily expressed by activated T cells, particularly Th17 cells, as well as other immune cells like γδ T cells and some innate immune cells ^[6]. The gene encodes the interleukin-17F (IL-17F) cytokine, a disulfide-linked homodimer protein that shares significant sequence homology with IL-17A ^[7]. Functionally, IL-17F is a pro-inflammatory cytokine that binds to the IL-17RA/RC receptor complex, triggering downstream signaling pathways involving Act1 and TRAF6, leading to the induction of various cytokines (like IL-6, IL-8, GM-CSF) and chemokines, which contribute to neutrophil recruitment and inflammation in barrier tissues such as the skin, lungs, and gut ^[8]. Elevated levels or dysregulation of IL-17F have been implicated in the pathogenesis of several autoimmune and inflammatory diseases, including psoriasis, rheumatoid arthritis, inflammatory bowel disease (like Crohn's disease and ulcerative colitis), and potentially Sjögren's syndrome, highlighting its role in chronic inflammatory processes ^[7-9]. The B6-huIL17A/huIL17F mouse is a dual-gene humanized model constructed by gene-editing technology. Based on the B6-hIL-17A mouse (catalog number: C001510), the sequences from the ATG start codon to the TGA stop codon of the endogenous mouse Il17f gene were replaced with the sequences from the ATG start codon to the TAA stop codon of the human IL17F gene. This model can be used for research on the pathogenesis of various chronic inflammatory diseases, such as rheumatoid arthritis (RA), psoriasis, multiple sclerosis, and inflammatory bowel diseases (IBD) and the related therapeutic drugs, as well as for the development of IL17A/IL17F-targeted drugs.

The B6-huIL4/huIL13/huTSLP mouse is a triple-gene humanized model obtained by mating B6-huIL4 mice (catalog number: C001628), B6-huIL13 mice (catalog number: C001634), and B6-huTSLP mice (catalog number: C001809). This model can be used for the mechanism research and development of treatment methods in allergic diseases, inflammation and autoimmune diseases, Th2 immune response, parasitic infections, tumor immunology, as well as the development of IL-4/IL13/TSLP-targeted drugs, and the pre-clinical evaluation of drug efficacy and safety.