IL13RA1 and glioblastoma: To investigate whether IL-13Rα1 mRNA expression is also associated with patient prognosis, Kaplan–Meier survival analysis was performed to assess survival of subjects with high IL-13Rα1 (Log2 ratio > 2) and no IL-13Rα1 mRNA (Log2 ratio < 0) expressing GBM tumors.