In this study using lentivirus-mediated IL-33 gene knockdown (IL33KD) and IL-33 overexpression (IL33oe) in rat C6 glioma cells and human glioma cell lines (U251MG and U87MG), we found that IL33oe-glioma cells had resistance to the insults of the alkylating agent, temozolomide (TMZ), possibly because of the increased expression of DNA repair genes (i.e., BRCA1, BRCA2, Rad51, FANCB, and FANCD) in IL33oe-glioma cells. This evidence concerns the gene BRCA1 and central nervous system cancer.