Mouse Interleukin-13 (IL-13) is a Th2-associated cytokine produced primarily by activated CD4⁺ T helper 2 (Th2) cells, group 2 innate lymphoid cells (ILC2s), mast cells, and basophils in mice (Mus musculus), where it plays a central role in regulating allergic inflammation, mucosal immunity, and tissue remodeling. IL-13 signals through receptor complexes composed of IL-13Rα1 and IL-4Rα, activating JAK/STAT6 pathways that promote IgE-associated responses, alternative (M2) macrophage activation, mucus production, and suppression of certain pro-inflammatory cytokines. Murine IL-13 is widely studied in experimental models of allergic airway disease (e.g., ovalbumin- or house dust mite–induced asthma models), where it drives airway hyperresponsiveness, goblet cell hyperplasia, eosinophilic infiltration, and airway remodeling. IL-13 also plays important roles in helminth infection models by promoting parasite expulsion and tissue repair, as well as in fibrosis models affecting the lung and liver. IL-13–deficient and STAT6-deficient mouse models have been instrumental in defining the molecular mechanisms of Th2 immunity and allergic pathology. As both a biomarker and therapeutic target, mouse IL-13 remains central to preclinical research on asthma, atopic disease, fibrosis, and development of cytokine-modulating therapies relevant to human type 2 inflammatory disorders.