Used to measure levels of interleukin-1 receptor antagonist (IL-1RA) in human biological samples such as serum, plasma, or cell culture supernatants. This kit is widely applied in clinical research and immunology studies to investigate inflammatory diseases including rheumatoid arthritis, type 2 diabetes, and autoimmune disorders. It helps assess immune response regulation since IL-1RA modulates the activity of pro-inflammatory cytokine IL-1. The assay supports biomarker discovery, therapeutic monitoring, and evaluation of drug efficacy in inflammation-related conditions.