Immunology has developed quite impressively over the past decade and perhaps very few fields in medicine or biology have grown so explosively. Completely new fields have been elucidated in depth. We recall only the definition of the nature and function of RLA antigens at the molecular level. the chemical and functional identification of several cytokines. and the correlation to particular immunological functions of specific epitopes present on cellular mem­ branes. The extensive application of immunological techniques and concepts to the neurological sciences has led to the development of neuroimmunology. a disci­ pline in its infancy until few years ago. In these last years. neuroimmunology has developed researches in various fields. RLA antigens were studied at the cellular level in brain samples and in CSF cells in several diseases. Cytokines. such as interleukin 1 and 2. gamma- and alpha-interferons. and tumor necrosis factor alpha. were studied at the immunohistological level and with quantitative methods in serum and CSF. With these data. new relevant insights were obtained on the molecular mechanisms underlying CNS immunological diseases. Moreover. neuroimmunological researches were carried on through the development of new and more 'specific' technologies for the study of natural and experimental diseases. the most important of which seem to be. at present. the techniques of cell cultures for cell lines specific to the CNS (oligodendrocytes. astroglia. microglia. meningeal cells. brain capillary cells and tumor cells).