Standard neurobiology textbooks commonly do not contain a chapter on cancer, and the word might not even appear in theindex. Its absence cannot be explained simply on the grounds that the subject falls more appropriately within the clinicalrealm, because you will find chapters devoted to various other nervous system diseases. Could this intellectual blind spotresult from the fact that mature neurons, being post-mitotic, do not succumb to the disease? This absence in most texts iscurious, considering the severe functional implications. The word is sometimes used metaphorically to connote an unstoppableprocess of destruction, and indeed some forms of brain cancer present the most dire prognosis of any cancer. But moreimportantly the neglect of this subject is curious, because on a molecular and cellular level, cancer is the result of biologicalprocesses that are at the forefront of modern neurobiological research. These include such current hot-topic areas as intraandinter-cellular signaling networks, regulation of gene transcription, control of cellular differentiation, regulation of cellmotility, migration and cell death; the secretion and response to growth factors, and interactions with the vascular andimmune systems. Finally, the current enthusiasm and promising research on the use of stem cells for therapeutic treatmentof nervous system disease has brought us face-to-face with our ignorance in this area, as we find that many types of stem cellstransplanted into the brain form tumors. This issue of Neuron Glia Biology contains a special collection of original researchpapers on cancer in the peripheral and central nervous system and a review on the subject. These papers are introduced belowby Special Feature Editor, Philip Lee.