Progression of gliomas to more malignant phenotypes involves numerous molecular genetic alterations. The genes affected by these alterations, the steps in malignant progression for which they are responsible, their normal function in controlling diverse cellular functions such as differentiation, signal transduction, cell cycle progression and angiogenesis and how they may act in concert with other tumour suppressor genes or oncogenes are some of the questions finally coming into focus and being studied. As other genes are discovered, their association with tumour progression can be assessed, coupled with current histopathology and used to determine more accurately patient prognosis and strategies for intervention. With the generation of specific reagents, such as monoclonal antibodies directed to glioma derived antigens or emerging gene therapy techniques designed to deliver toxic, antisense or reconstituting genes specifically to tumour tissue, new approaches will be devised that may finally be used to treat these tumours effectively.