The MYC oncogene family comprises regulatory genes and proto-oncogenes that encode transcription factors, involved in various cellular processes such as the cell cycle, apoptosis, DNA repair, and metabolism. Members include c-Myc (MYC), l-Myc (MYCL), and n-Myc (MYCN). c-Myc (MYC) is a basic helix-loop-helix leucine zipper (bHLHZip) transcription factor, which forms heterodimers with Max protein to bind DNA and regulate the expression of approximately 15% of genes, thereby participating in key cellular processes such as cell proliferation, apoptosis, DNA repair, and metabolism. In many cancers, c-Myc is overexpressed, leading to uncontrolled cell proliferation and tumor growth, such as in Burkitt's lymphoma where c-Myc gene rearrangement is common. Dysregulation of the MYC oncogene plays a crucial role in tumorigenesis, predominantly through transcriptional dysregulation resulting in overexpression of c-Myc protein. Alb-Cre+/hMYC-IRES-EGFP+ mice are generated by crossing H11-CAG-LSL-hMYC-IRES-EGFP mice (Catalog Number: C001338), which conditionally express the human c-Myc oncogene, with Alb-Cre mice that express Cre recombinase specifically in hepatocytes under the control of the Alb promoter. The Cre-mediated recombination results in the deletion of the transcriptional stop sequence (Loxp-Stop-Loxp, LSL) in H11-CAG-LSL-hMYC-IRES-EGFP mice, leading to overexpression of the MYC oncogene in the liver and subsequent carcinogenesis. This model, therefore, spontaneously develops liver cancer with an early onset.

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]. This strain was generated by mating B6-hLPA(CKI) mice (catalog number: C001521) with Alb-Cre mice (liver-specific Cre-expressing mice), resulting in a mouse model with liver-specific overexpression of the human LPA gene. B6-hLPA(CKI)/Alb-cre mice can be used to study the relationship between the LPA gene and hyperlipidemia and related cardiovascular diseases.

Inhibin βE subunit (INHBE) is a member of the transforming growth factor-β (TGF-β) superfamily, highly specifically expressed in liver cells. The precursor protein of INHBE generates the inhibin β subunit after proteolytic processing. This protein is associated with various cellular processes, including cell proliferation, apoptosis, immune response, and hormone secretion. During the development of obesity and diabetes, the expression of INHBE protein inhibits the proliferation and growth of relevant cells in the pancreas and liver. Research has found a positive correlation between INHBE expression in the liver and insulin resistance and body mass index (BMI), suggesting that INHBE may be a liver factor in altering systemic metabolic status under conditions of obesity-related insulin resistance ^[1]. The studies conducted by Alnylam Pharmaceuticals and the Regeneron Genetics Center (RGC), respectively, revealed the close relationship between INHBE and fat regulation. The research demonstrated that rare loss-of-function variants in INHBE may protect the liver from the impact of inflammation, abnormal blood lipids, and type 2 diabetes by promoting healthy fat storage. Patients carrying such mutations exhibit more normal fat distribution, significantly reduced abdominal fat, improved metabolic conditions, and a decreased risk of cardiovascular diseases and type 2 diabetes ^[2-4]. These findings suggest that INHBE is a liver-specific negative regulator of fat storage. Inhibiting the expression of INHBE genes and proteins may be a potential strategy for treating metabolic disorders related to improper fat distribution and storage. Consequently, several small nucleic acid pharmaceutical companies, including Alnylam Pharmaceuticals, Arrowhead Pharmaceuticals, and Wave Life Sciences, are currently developing RNA interference (RNAi) drugs targeting INHBE to treat obesity ^[5-7]. The leptin (LEP) gene, also known as the OB gene, encodes the leptin protein, which is secreted into the circulation by white adipocytes and plays a major role in regulating energy homeostasis. Circulating leptin binds to leptin receptors (LEPR) in the brain, activating downstream signaling pathways that inhibit feeding and promote energy expenditure. Leptin also has multiple endocrine functions and is involved in physiopathological processes such as immune and inflammatory responses, hematopoiesis, angiogenesis, reproduction, bone formation, and wound healing ^[8]. Mutations in the LEP gene and its regulatory regions lead to severe obesity and morbid obesity with hypogonadism in humans and are also associated with the development of type II diabetes ^[9]. The B6-hINHBE/ob mouse model, generated by mating B6-hINHBE mice (Catalog Number: C001533) with Lep KO (ob/ob) mice (Catalog Number: C001368), is a metabolic disease model. It can be used for research on obesity, type II diabetes, and metabolic diseases related to improper fat distribution and storage, and for the development of human INHBE-targeted therapies.

The tau protein, a microtubule-associated protein encoded by MAPT is primarily localized to neuronal axons and plays a critical role in microtubule stability and assembly. By binding to microtubules, tau protein helps to maintain neuronal cell shape. Mutations in MAPT can promote tau aggregation, leading to pathological tau protein accumulation and death of glutamatergic cortical neurons ^[1]. Additionally, certain MAPT mutations can affect pre-mRNA exon splicing, altering the ratio of 3R to 4R tau protein isoforms and increasing the relative production of 4R-tau protein, which is more prone to fibril formation ^[2]. The GLP-1 receptor (GLP-1R) gene encodes a protein that serves as the receptor for the glucagon-like peptide 1 (GLP-1) hormone, belonging to the glucagon receptor subfamily within the class B G-protein-coupled receptors (GPCRs). G proteins are a class of intracellular signal transduction proteins typically associated with seven-transmembrane receptors (GPCRs). When a GPCR binds to its ligand, it activates the G protein, causing it to dissociate from the Gβγ subunit and initiate downstream effects through interactions with membrane-bound effector molecules. This signaling process is known as canonical G protein signaling. GLP-1R is a multi-transmembrane protein characterized by a typical seven-transmembrane core domain and a relatively large extracellular domain, which can stimulate glucose-induced insulin secretion ^[3]. GLP-1R is a cell surface receptor protein widely expressed in tissues such as the brain, small intestine, heart, and lungs. It internalizes in response to GLP-1 and GLP-1 analogs and plays a crucial role in the insulin secretion signaling cascade. Additionally, data from animal models indicate its neuroprotective effects ^[4-5]. Polymorphisms of this gene are closely associated with diabetes. The GLP1R protein is an important drug target for treating type 2 diabetes and stroke. Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are a new class of antidiabetic drugs in recent years. They activate GLP1R to enhance insulin secretion, suppress glucagon secretion, delay gastric emptying, and reduce food intake through central appetite suppression, lowering blood glucose and weight loss ^[6]. The B6-htau/hGLP-1R mouse is obtained by mating B6-htau mice (Catalog No.: C001410) with B6-hGLP-1R mice (Catalog No.: C001421). This model can be used for research on neurodegenerative diseases such as frontotemporal dementia (FTD) and Alzheimer's disease (AD), as well as metabolic diseases such as obesity and type 2 diabetes. It is also useful for developing GLP-1 receptor agonist (GLP-1RA) drugs or for the preclinical evaluation of the potential therapeutic effects of GLP-1RA drugs in tauopathy-related diseases like Alzheimer's disease (AD).

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 B6-hPD-1/hVEGFA mouse is a humanized model obtained by crossbreeding hPD-1 mice (Catalog No. C001524) with B6-hVEGFA 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.