Mouse Interleukin-10 (IL-10) is a key anti-inflammatory cytokine produced by regulatory T cells (Tregs), Th2 cells, macrophages, dendritic cells, and certain B-cell subsets in mice (Mus musculus), where it plays a central role in limiting excessive immune activation and maintaining immune homeostasis. IL-10 signals through the IL-10 receptor complex (IL-10R1/IL-10R2), activating JAK/STAT3 pathways that suppress pro-inflammatory cytokine production (including IL-1β, TNF-α, IL-6, and IFN-γ), reduce antigen presentation, and downregulate Th1- and Th17-type immune responses. Murine IL-10 is critical in experimental models of inflammatory bowel disease (IBD), where IL-10–deficient mice spontaneously develop colitis, highlighting its essential role in mucosal tolerance and gut immune regulation. IL-10 also modulates immune responses in models of sepsis, autoimmune diseases (such as experimental autoimmune encephalomyelitis), asthma, metabolic inflammation, cancer, and chronic infections including LCMV and Mycobacterium species. While IL-10 protects tissues from immune-mediated damage, excessive IL-10 can impair pathogen clearance and promote chronic infection or tumor immune evasion. As both a biomarker and functional regulator of immune balance, mouse IL-10 is extensively studied in preclinical research to understand cytokine network regulation, immune tolerance mechanisms, and development of immunomodulatory therapies relevant to human inflammatory, autoimmune, and infectious diseases.