Interleukin-18 (IL-18) is a proinflammatory cytokine of the IL-1 family with critical roles in innate and adaptive immunity. Signaling through the IL-18Rα/β receptor complex, it activates NF-κB and MAPK pathways to induce IFN-γ, TNF, and other inflammatory mediators. IL-18 synergizes with IL-12 and IL-15 to promote Th1 polarization, stimulating NK cells, CD8⁺ T cells, and Th1 lymphocytes. Dysregulated IL-18 activity is linked to autoimmune disorders, cardiovascular and metabolic disease, cancer, and chronic inflammation. In the CNS, IL-18 contributes to neuroinflammation, Alzheimer’s pathology, and injury responses. Catalina’s IL-18 antibodies have passed rigorous validation, delivering high sensitivity and specificity for accurate IL-18 detection.