Recent studies of experimental models of membranous glomerulonephritis (MGN) induced by immunization against preparations of brush border have shown that in the classical model described by Heymann, the subepithelial immune deposits are formed in situ by binding of free circulating antibody to a 330 kDa glycoprotein expressed by tubular and glomerular epithelial cells. The role of other brush border antigens has been demonstrated in related models. The importance in pathology of the properties of the target antigens as well as of the secondary events taking place after the initial antigen antibody interaction has been established. The development of biochemical and immunological techniques will make it possible to extend these observations to human pathology.