IL10 is a major immune regulatory cytokine that functions as a potent anti-inflammatory mediator acting on multiple immune cell types 1. Mechanistically, IL10 binds to a heterotetrameric receptor (IL10RA/IL10RB) triggering JAK1-mediated phosphorylation and STAT3 activation, which translocates to the nucleus to drive expression of anti-inflammatory mediators 23. IL10 targets antigen-presenting cells including macrophages and monocytes, inhibiting their production of pro-inflammatory cytokines (TNF, IL-6, IL-8, GM-CSF, G-CSF, IL-1α/β) while reducing MHC-II and co-stimulatory molecule expression to suppress T cell activation 4567. IL10 also maintains tissue homeostasis during infection and inflammation through upregulation of innate immunity and promotion of tissue repair 1. Regulatory B cell subsets, particularly plasma cells, produce IL10 to mediate suppressive immune functions during autoimmune and infectious diseases 8. In disease contexts, IL10 plays complex roles: CD169+ macrophages produce IL10 to mitigate sepsis mortality 9, while IL10 can alternatively promote immunosuppression in glioblastoma microenvironments 10. Elevated IL10 serves as a biomarker for primary CNS lymphoma diagnosis 11, and IL10 polymorphisms associate with community-acquired pneumonia susceptibility 12.