Pro-inflammatory cytokine primarily involved in epithelial barrier repair， polarized T-helper 1 (Th1) cell and natural killer (NK) cell immune responses (PubMed:26638072， PubMed:26638073). Upon binding to IL18R1 and IL18RAP， forms a signaling ternary complex which activates NF-kappa-B， triggering synthesis of inflammatory mediators (By similarity). Synergizes with IL12/interleukin-12 to induce IFNG synthesis from T-helper 1 (Th1) cells and natural killer (NK) cells (By similarity). Involved in transduction of inflammation downstream of pyroptosis: its mature form is specifically released in the extracellular milieu by passing through the gasdermin-D (GSDMD) pore (PubMed:30392956).