The FAP gene (Fibroblast Activation Protein alpha) encodes a homodimeric integral membrane serine protease that plays a crucial role in extracellular matrix degradation and various cellular processes, including tissue remodeling, wound healing, fibrosis, and tumor growth ^[1]. While its expression is typically very low in normal adult tissues, FAP is selectively and highly expressed in reactive stromal fibroblasts of epithelial cancers, granulation tissue of healing wounds, and malignant cells of bone and soft tissue sarcomas ^[2]. The protein functions as both a dipeptidyl peptidase and an endopeptidase, cleaving specific sequences in various bioactive peptides and structural proteins, such as neuropeptide Y and denatured collagen ^[3]. This specific expression pattern makes FAP a promising target for imaging and therapy in oncology, as it labels cancer-associated fibroblasts (CAFs) in over 90% of human carcinomas ^[4]. The B6-hFAP mouse is a humanized model constructed by replacing the sequence from ATG start codon to partial intron 2 of the mouse Fap gene with the Kozak Human FAP CDS-3'UTR of Mouse Fap-WPRE-BGH pA cassette. B6-hFAP mice can be used for research into the pathogenesis of various malignant tumors, as well as for the screening, development, and safety evaluation of FAP-targeted drugs.

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

Nipsnap2 is located on chromosome 5 of mice. Nuclease Technology will be used to design sgRNA; Nipsnap2 knockout mice will be obtained by applying high-throughput electroporation of fertilized eggs. After sexual maturity, sperm were collected for cryopreservation.