Moreover, IL-33 has been observed in a number of cancers where an elevated level of IL-33 has been detected in the serum and tumor tissue of patients with gastric cancer116, hepatocellular carcinoma117, uterine leiomyoma118, lung cancer119, colorectal cancer120,121, breast cancer122, endometrial cancer123, and recently in glioma where IL-33 expression was shown to correlate with glioma grade, Panofsky performance score, and survival61. This evidence concerns the gene IL33 and central nervous system cancer.