Although IL-18 is perceived as an anticancer cytokine, high concentrations of IL-18 have been associated with advanced tumor stages in patients with seven tumor types (pancreatic cancer, esophageal squamous cell carcinoma, breast cancer, hepatocellular carcinoma, lung cancer, renal cell carcinoma, multiple myeloma, and oral cavity cancer) [5, 6]. This evidence concerns the gene IL18 and plasma cell myeloma.