IL4 and Cachexia: Moreover, eosinophils induce catecholamine production in macrophages via the IL-4/13-IL-4Rα-STAT6 signaling axis, triggering thermogenic gene expression in BAT and promoting lipolysis in WAT.282,283 Furthermore, in a cancer cachexia mouse model, researchers reported an increase in the number of IL-4-induced M2 macrophages, which express neurotrophic factors that promote a neuroprotective milieu, within the inguinal WAT.