Interleukin 37, also known as Interleukin 1 Zeta (IL1z), is an anti-inflammatory cytokine. Interleukines are cytokines that make an important part of immune signaling. It belongs to the interleukin-1 family. IL-37 plays a role in protecting the body against endotoxin shock, ischemia-reperfusion injury, autoimmune diseases, and cardiovascular diseases. In addition, IL-37 has a potential antitumor effect. Besides, Interleukin 18 Receptor 1 (IL18R1) has been identified as an interactor of IL1z, thus a binding ELISA assay was conducted to detect the interaction of recombinant human IL1z and recombinant human IL18R1. Briefly, IL1z were diluted serially in PBS, with 0.01% BSA (pH 7.4). Duplicate samples of 100μl were then transferred to IL18R1-coated microtiter wells and incubated for 2h at 37℃. Wells were washed with PBST and incubated for 1h with anti-IL1z pAb, then aspirated and washed 3 times. After incubation with HRP labelled secondary antibody, wells were aspirated and washed 3 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 IL1z and IL18R1 was shown in Figure 1, and this effect was in a dose dependent manner.