Interleukin 10 (IL10) is an anti-inflammatory cytokine primarily produced by immune cells, including macrophages, T cells, and B cells. It plays a crucial role in limiting excessive immune responses, preventing tissue damage, and maintaining immune homeostasis. IL10 suppresses pro-inflammatory cytokine production and antigen presentation, making it vital in controlling autoimmune diseases, infections, and chronic inflammation. Its signaling through the IL10 receptor (IL10R) activates the JAK-STAT pathway, modulating immune cell function. Dysregulation of IL10 is associated with inflammatory disorders and cancer.Besides,Interleukin 6 (IL6) has been identified as an interactor of IL10, thus a functional binding ELISA assay was conducted to detect the interaction of recombinant mouse IL10 and recombinant horse IL6 . Briefly, biotin-linked IL10 were diluted serially in PBS, with 0.01% BSA (pH 7.4). Duplicate samples of 100μl were then transferred to IL6-coated microtiter wells and incubated for 1h at 37℃. Wells were washed with PBST 3 times and incubation with Streptavidin-HRP for 30min, then wells were aspirated and washed 5 times. With the addition of substrate solution, wells were incubated 15-25 minutes at 37℃. Finally, add 50µl stop solution to the wells and read at 450nm immediately. The binding activity of IL10 and IL6 was shown in Figure 1, the EC50 for this effect is 0.56µg/mL.