There is no good treatment for malignant brain tumors that come back after surgery, radiation therapy and/or chemotherapy. A new experimental treatment for recurrent malignant brain tumors has been developed that uses a new type of anti cancer drug called a targeted protein toxin. The purpose of the study is to find out if this new experimental drug, IL-4toxin, a targeted protein toxin, can be used safely and effectively in patients with malignant brain tumors. The study is designed to find and test the effectiveness of the drug and to look for any side effects when it is given directly into brain tumors in a larger number of patients than already studied.