In fact, consistent with previous reports [13], we find that THP-1 cells show induction of IL13Rα2 mRNA 13 to 15-fold after overnight treatment with TNF and IL-13 or IL-4, although the level of IL13Rα2 expression was more than 13.6-fold lower than that expressed by the U251T glioma cell line and not at sufficient levels to be detected by flow cytometry using the IL13Rα2-specfic AF146 antibody. This evidence concerns the gene IL4 and central nervous system cancer.