IL13 and glioblastoma: IL13 interacts strongly with the high-affinity receptor IL13Rα2 (15), which is a versatile therapeutic target due to its rare expression in normal tissue (16) and overexpression in many human cancers, including glioblastoma (GBM) (17), pancreatic ductal adenocarcinoma (18), melanoma (19), ovarian carcinoma (20), clear cell renal cell carcinoma (21), breast cancer (22), and lung cancer (23).