Lipoprotein A (LPA) is a type of particle similar to low-density lipoprotein (LDL) that is considered one of the risk factors for cardiovascular disease (CVD), such as atherosclerosis, coronary heart disease, stroke, etc ^[1]. LP(a) is similar in size and lipid content to LDL (low-density lipoprotein) and also contains the lipoprotein ApoB-100. However, unlike LDL, LP(a) additionally contains a variable-length lipoprotein called Apo(a), which covalently binds to ApoB-100 through a single disulfide bond. LP(a) plays an important role in systemic lipid transport, guiding inflammatory cells into blood vessel walls and leading to smooth muscle cell proliferation. Furthermore, it is involved in wound healing and tissue repair, interacting with the components of blood vessel walls and the extracellular matrix ^[2]. However, LP(a) can also cause arterial narrowing by adhering to the arterial wall, accelerating the formation of blood clots, and thereby triggering a series of pathological changes related to coronary heart disease, cardiovascular disease, atherosclerosis, thrombus formation, and stroke ^[3]. The plasma concentration of LP(a) is closely related to genetic factors and is primarily regulated by the LPA gene. Therefore, the LPA gene is an important potential target for cardiovascular disease treatment. The LPA gene encodes a serine protease that inhibits the activity of tissue-type plasminogen activator I. Fragments of this protein, generated through protein hydrolysis, can adhere to atherosclerotic lesions in arteries, promoting blood clot formation. The LPA gene is expressed in both humans and non-human primates but is not expressed in mice. Constructing mouse models expressing the human LPA gene is of significant importance for developing lipid-lowering drugs, which can drive the development of novel therapies for cardiovascular diseases. Currently, various novel therapies targeting the transcription rate of the LPA gene are under development, including small interfering RNA (siRNA) and antisense oligonucleotides (ASO) ^[4]. Proprotein convertase subtilisin/kexin 9 (PCSK9) is a serine protease primarily produced in the liver but expressed in other tissues, including the intestine, heart, and neurons. The N-terminal domain of the PCSK9 protein is responsible for protein localization and stability, while the C-terminal domain is responsible for protein enzymatic activity ^[5]. The Low-density lipoprotein receptor (LDLR) is a receptor that is responsible for clearing low-density lipoprotein cholesterol (LDL-C) from the blood. PCSK9 cleaves the intracellular domain of LDLR on the cell surface, causing it to detach from the cell membrane and be transported to the lysosome for degradation, promoting LDLR degradation, and increasing plasma LDL-C. Overexpression or gain-of-function mutations of the PCSK9 gene can lead to LDL-C accumulation by reducing LDLR levels. This can cause hypercholesterolemia, which increases the risk of cardiovascular diseases, such as atherosclerosis and coronary heart disease, and neurodegenerative diseases, such as Alzheimer's disease ^[6]. PCSK9 has emerged as a key target for the development of lipid-lowering drugs. Several PCSK9-targeted antibodies or small nucleic acid drugs have been approved for marketing worldwide, including evolocumab from Amgen, alirocumab from Sanofi and Regeneron, and inclisiran from Novartis. These drugs primarily work by inhibiting PCSK9 activity or preventing PCSK9 protein from binding to LDLR, lowering LDL-C levels in the blood to treat hypercholesterolemia ^[7-8]. In addition, PCSK9 can promote tumor growth and development by regulating cell proliferation, migration, and invasion. It can also regulate the expression of inflammatory factors that contribute to inflammation. Therefore, targeting the expression of PCSK9 has been investigated in tumor immunotherapy and autoimmune disease therapy ^[9-10]. The B6-hLPA (CKI)/Alb-cre/hPCSK9 mouse model is generated by crossing B6-hLPA (CKI) mice (Catalog No.: C001521, a mouse strain with conditional expression of the human LPA gene), Alb-Cre mice (liver-specific Cre-expressing mice), and B6-hPCSK9 mice (Catalog No.: C001617). This model harbors two cardiovascular disease risk factors, namely Lp (a) (lipoprotein (a)) and PCSK9, making it suitable for research on hyperlipidemia, stroke, coronary heart disease, and other atherosclerotic cardiovascular diseases (ASCVD).

Programmed cell death protein 1 (PDCD1/PD-1) is a member of the B7-CD28 costimulatory receptor family. It is an inhibitory receptor expressed on activated T cells and plays a role in regulating the function of effector T cells, including CD8+ T cells, and promoting the differentiation of CD4+ T cells into regulatory T cells. PD-1 is expressed in a variety of tumors and plays an important role in antitumor immunity. In addition, PD-1 is involved in the defense against autoimmune diseases and has inhibitory effects on antitumor and antimicrobial immunity ^[1]. PD-1 binds to programmed death ligands 1 and 2 (PD-L1 and PD-L2) to inhibit T cell activation, reduce the production of corresponding cytokines, and regulate T cell survival ^[2]. Drugs targeting this pathway can reactivate T cells to activate antitumor immune responses ^[3]. The Vascular Endothelial Growth Factor (VEGF) family is a group of particular endothelial growth factors intimately associated with angiogenesis. These factors promote increased vascular permeability, extracellular matrix degeneration, vascular endothelial cell migration and proliferation, and are capable of stimulating angiogenesis and increasing the permeability of existing vessels. As such, they play a pivotal role in normal vascular development and wound healing. The VEGF family comprises VEGFA, VEGFB, VEGFC, VEGFD, VEGFE, and PLGF ^[4]. Of these, VEGFA is the most commonly targeted in research related to neovascular ophthalmic diseases due to its crucial role in the proliferation, migration, and formation of endothelial cell microvessels ^[5]. Overexpression of VEGFA in the eye can result in abnormal vascular growth and leakage, leading to various ophthalmic diseases such as Age-Related Macular Degeneration (AMD), Diabetic Retinopathy (DR), and corneal neovascularization ^[5-6]. The progression of solid tumors depends on vascularization and angiogenesis within malignant tissues, with VEGFA playing a crucial role among various pro-angiogenic factors. The VEGFA gene is upregulated in many known tumors, correlating with tumor staging and progression. Blocking VEGFA may lead to vascular network regression, inhibiting tumor growth ^[7]. Thus, VEGFA is an important target for anti-angiogenic cancer therapies. The huPD-1/huVEGFA mouse is a humanized model obtained by crossbreeding huPD-1 mice (Catalog No. C001524) with huVEGFA mice (Catalog No. C001555). This model can be used for research in drug development, efficacy and safety evaluation, tumor immunotherapy evaluation, and immune system mechanisms related to human PD-1/VEGFA.

The TNFRSF9 gene, also known as 4-1BB/CD137, encodes a protein that belongs to the TNF receptor superfamily. This receptor aids in the clonal expansion, survival, and development of T cells. It can also induce the proliferation of peripheral monocytes, enhance TCR/CD3-triggered activation-induced T cell apoptosis, and regulate CD28 co-stimulation to promote Th1 cell responses. TRAF adaptor proteins can bind to it and transmit signals that activate NF-kappaB. Many immune cell types express TNFRSF9, including activated NK cells, NKT cells, B cells, eosinophils, basophils, mast cells, neutrophils, mature Tregs, activated monocytes, and dendritic cells. Additionally, TNFRSF9 may be expressed in non-immune cell types such as endothelial cells, neurons, astrocytes, and microglia. TNFRSF9 plays roles in innate and adaptive immunity, including cancer immunology and autoimmune diseases ^[1]. Due to its broad expression profile and immune response functions, 4-1BB is a potential target for cancer and immunotherapy. In recent years, research on second-generation 4-1BB agonists has been expanding, with various strategies being implemented to overcome the liver toxicity and efficacy limitations of the first generation ^[2-3]. Programmed cell death 1 ligand 1 (PD-L1), also known as cluster of differentiation 274 (CD274) or B7 homolog 1 (B7H1), is an immune inhibitory receptor ligand. PD-L1 is a type I transmembrane protein with immunoglobulin V-like (IgV) and C-like (IgC) structural domains and is expressed by hematopoietic and non-hematopoietic cells, including T cells, B cells, and various types of tumor cells ^[4]. PD-L1 can bind to the PD-1 on the surface of CD8+ T cells, inhibiting the activity of CD8+ T cells. This interaction can prevent the immune system from damaging normal tissues, but it can also be used by tumor cells to escape immune surveillance. Monoclonal antibodies that competitively bind to PD-L1 can relieve the immune function inhibition mediated by the binding of PD-1 and PD-L1. This can reactivate CD8+ T cells, triggering the human body's anti-tumor immune response ^[5]. Therefore, development of antibody drugs targeting PD-1 and PD-L1 is a hot area in tumor immunotherapy ^[5-7]. hu4-1BB/hPDL1-V(2) mice are TNFRSF9 and CD274 double humanized mouse models obtained by mating TNFRSF9 humanized mouse models (Catalog No. C001604) with CD274 humanized mouse models (Catalog No. C001235). They express human TNFRSF9 and CD274 genomic sequences under the control of mouse promoters. This model is a valuable tool for studying cancer immunotherapy. In addition, this model also provides a powerful preclinical research platform for evaluating the efficacy and mechanism of therapeutic drugs targeting TNFRSF9 and CD274.

The Vascular Endothelial Growth Factor (VEGF) family is a group of particular endothelial growth factors intimately associated with angiogenesis. These factors promote increased vascular permeability, extracellular matrix degeneration, vascular endothelial cell migration and proliferation, and are capable of stimulating angiogenesis and increasing the permeability of existing vessels. As such, they play a pivotal role in normal vascular development and wound healing. The VEGF family comprises VEGFA, VEGFB, VEGFC, VEGFD, VEGFE, and PLGF ^[1]. Of these, VEGFA is the most commonly targeted in research related to neovascular ophthalmic diseases due to its crucial role in the proliferation, migration, and formation of endothelial cell microvessels ^[2]. Overexpression of VEGFA in the eye can result in abnormal vascular growth and leakage, leading to various ophthalmic diseases such as Age-Related Macular Degeneration (AMD), Diabetic Retinopathy (DR), and corneal neovascularization ^[2-3]. The progression of solid tumors depends on vascularization and angiogenesis within malignant tissues, with VEGFA playing a crucial role among various pro-angiogenic factors. The VEGFA gene is upregulated in many known tumors, correlating with tumor staging and progression. Blocking VEGFA may lead to vascular network regression, thereby inhibiting tumor growth ^[4]. Thus, VEGFA is an important target for anti-angiogenic cancer therapies. Angiopoietin-2 (ANG2/ANGPT2), encoded by the ANGPT2 gene, is a secreted glycoprotein of the angiopoietin family predominantly expressed in vascular endothelial cells and stored in Weibel-Palade bodies for rapid release. ANGPT2 regulates vascular biology in a context-dependent manner by binding to the Tie2 tyrosine kinase receptor, playing pivotal roles in angiogenesis and vascular remodeling ^[5]. Its molecular structure includes a coiled-coil domain facilitating oligomerization and a fibrinogen-like domain critical for receptor binding. Functionally, ANGPT2 acts as a partial Tie2 receptor antagonist to Angiopoietin-1 (ANG1). Through competitive inhibition of Tie2 signaling, ANGPT2 disrupts vascular endothelial homeostasis, inducing increased vascular permeability and structural plasticity. In synergy with vascular endothelial growth factor (VEGF), ANGPT2 drives angiogenic sprouting and pathological neovascularization. Conversely, under conditions of low or absent VEGF, it mediates vascular regression ^[6-7]. ANGPT2 plays a central pathological role in vascular proliferative diseases such as tumor angiogenesis, diabetic retinopathy, and age-related macular degeneration. Endothelial cell activation and inflammatory responses mediated by ANGPT2 also contribute to the pathogenesis of inflammatory conditions including sepsis and rheumatoid arthritis ^[8]. Therapeutic strategies targeting ANGPT2 include monoclonal antibodies (e.g., Nesvacumab) and peptide-Fc fusion proteins (e.g., Trebananib), often combined with VEGF inhibitors to enhance anti-angiogenic efficacy ^[9-10]. Current research efforts are focused on optimizing ANGPT2/VEGF dual-target inhibition strategies and developing biomarkers, aiming to improve clinical outcomes in tumors and ocular vascular diseases and validate its translational value as a therapeutic target in vascular and inflammatory diseases ^[11-12]. huANGPT2/huVEGFA mice are VEGFA and ANGPT2 double humanized mouse models obtained by mating VEGFA humanized mouse models (Catalog No. C001555) with ANGPT2 humanized mouse models (Catalog No. C001615). huANGPT2/huVEGFA mice express human VEGFA and ANGPT2 genomic sequences under the control of mouse promoters. This model is capable of reproducing human VEGFA and ANGPT2 and is a valuable tool for studying cancer, vascular diseases and autoimmune disorders. In addition, this model also provides a powerful preclinical research platform for evaluating the efficacy and mechanism of therapeutic drugs targeting VEGFA and ANGPT2.

huCD28/huCD3 mice are a dual-gene humanized model obtained by mating huCD28 mice (catalog ID: C001817) with huCD3 mice (catalog ID: C001325). This model can be used for the research on autoimmune diseases such as rheumatoid arthritis (RA), Sjögren's syndrome, and systemic sclerosis, transplant rejection, malignant tumors such as T-cell lymphoma, acute myeloid leukemia, and breast cancer, as well as chronic infections such as HIV. It is also used for the screening, development, and safety evaluation of CD28/CD3-targeted drugs.

Cluster of Differentiation 3 (CD3) is a protein complex that acts as a co-receptor for T cells and is involved in the activation of cytotoxic T cells (CTLs) and helper T cells (THs). CD3 consists of five polypeptide chains: γ, δ, ε, ζ, and η, all of which are transmembrane proteins. The transmembrane regions of CD3 molecules connect with the transmembrane regions of TCR's two polypeptide chains through salt bridges, forming the TCR-CD3 complex, which is essential for T cell antigen recognition ^[1-2]. After TCR recognizes an antigen, the activation signal is transduced by CD3 into the T cell. CD3 is highly specific at all developmental stages of T cells, thus it is considered a T cell-specific immunohistochemical marker. Additionally, CD3 is present in almost all T cell lymphomas and leukemias and can be used to distinguish between morphologically similar B cell and bone marrow tumors. Due to its significant role in T cell activation and antigen recognition, CD3 is an important drug target in immunosuppressive therapy for type 1 diabetes and other autoimmune diseases ^[3]. The EPCAM gene encodes a transmembrane glycoprotein, Epithelial Cell Adhesion Molecule (EPCAM), also known as CD326 or Trop-1, which mediates calcium-independent homotypic cell adhesion and participates in fundamental processes including cell adhesion, migration, proliferation, and signal transduction, thereby maintaining epithelial tissue integrity ^[4]. While normally expressed on the surface of epithelial cells in organs such as the gastrointestinal tract, lungs, and skin, EPCAM is frequently overexpressed in various cancers, including colorectal, breast, and pancreatic carcinomas, but is largely absent or weakly expressed in healthy squamous epithelia ^[4]. Structurally, EPCAM comprises an extracellular domain (EpEX) mediating intercellular adhesion, a transmembrane domain, and a short intracellular domain (EpICD). Upon proteolytic cleavage by ADAM17 and γ-secretase, EpICD translocates to the nucleus, activating oncogenic pathways such as Wnt/β-catenin, ERK, and FAK-AKT, which promotes epithelial-mesenchymal transition (EMT), tumor progression, and metastasis ^[5]. Notably, EPCAM serves as a marker for circulating tumor cells (CTCs) and cancer stem cells, and its downregulation during EMT can complicate advanced cancer detection ^[5-6]. Furthermore, dysregulated EPCAM expression is associated with congenital tufting enteropathy (CTE), a severe intestinal epithelial dysfunction ^[5]. Given its involvement in tumor metastasis through interaction with HGFR (c-Met), targeting EPCAM with strategies like the neutralizing antibody EpAb2-6 in combination with HGFR inhibitors has shown promising preclinical efficacy ^[7]. The huCD3/huEPCAM mouse is obtained by crossbreeding huCD3EDG mice (Catalog No.: C001325) with huEPCAM mice. It can be used for the development of CD3/EPCAM-targeted drugs, as well as for research in tumor immunotherapy and autoimmune disease-related drugs.

Cluster of Differentiation 3 (CD3) is a protein complex that acts as a co-receptor for T cells and is involved in the activation of cytotoxic T cells (CTLs) and helper T cells (THs). CD3 consists of five polypeptide chains: γ, δ, ε, ζ, and η, all of which are transmembrane proteins. The transmembrane regions of CD3 molecules connect with the transmembrane regions of TCR's two polypeptide chains through salt bridges, forming the TCR-CD3 complex, which is essential for T cell antigen recognition ^[1-2]. After TCR recognizes an antigen, the activation signal is transduced by CD3 into the T cell. CD3 is highly specific at all developmental stages of T cells, thus it is considered a T cell-specific immunohistochemical marker. Additionally, CD3 is present in almost all T cell lymphomas and leukemias and can be used to distinguish between morphologically similar B cell and bone marrow tumors. Due to its significant role in T cell activation and antigen recognition, CD3 is an important drug target in immunosuppressive therapy for type 1 diabetes and other autoimmune diseases ^[3]. Cluster of Differentiation 20 (CD20), also known as MS4A1, is a functional receptor molecule on the surface of B lymphocytes, closely associated with B cell activation, signal transduction, and growth regulation. CD20 is expressed in the late stages of B cell lymphopoiesis and disappears after differentiation into plasma cells. Therefore, CD20 is expressed from pre-B cells to mature B cells, but not in plasma cells ^[4]. It is highly expressed in most B-cell lymphomas. Since 1997, the advent of anti-CD20 monoclonal antibodies such as Rituximab has significantly improved the treatment outcomes for B cell malignancies. Therapeutic monoclonal antibodies (mAbs) targeting the CD20 antigen are widely used in research on B cell-depleting tumor therapies to treat various cancers and autoimmune diseases ^[5-7]. With the development of combination therapies, CD3/CD20 bispecific antibodies have gained significant attention from researchers. These antibodies can bind to CD20 on cancer cells and CD3 on T cells, promoting local T cell activation and cancer cell killing ^[8]. Currently, four CD3/CD20 bispecific antibodies have been approved for marketing: Epcoritamab (AbbVie/Genmab), Mosunetuzumab (Roche/Biogen), Glofitamab (Roche), and Odronextamab (Regeneron). The huCD3/huCD20 mouse is obtained by crossbreeding huCD3 mice (Catalog No.: C001325) with huCD20 mice. It can be used for the development of CD3/CD20-targeted drugs, as well as for research in tumor immunotherapy and autoimmune disease-related drugs.