The present application provides compositions and methods useful for the diagnosing and treating malignant gliomas. As described herein, the compositions and methods are based on the development of HLA class II binding peptides and peptide antigens encoded by the MAGE-A3 and IL-13Rα2 tumor associated genes, which stimulate the activity and proliferation of CD4+ T lymphocytes. In embodiments described herein, the compositions may induce a therapeutic response against malignant gliomas.
