IL18 and central nervous system cancer: Figures 2H,I show that the protein concentration of IL-18 was 8 times higher in gliomas as compared to normal brain tissues, while the protein concentration of IL-1β was 3 times higher. Mechanistically, the increased protein expressions of IL-18 and IL-1β may also be explained by transcriptional regulation because mRNA levels of IL-18 and IL-1β were significantly increased (Figures 2J,K).