The localization of the α2,α3 and α6 subunits of the β1 integrin family on different cells of the glomerular capillary wall and on juxtacapillary mesangium was investigated using an immunoelectron microscopic technique on freshly harvested normal human glomeruli. α2,β1, α3β1 and α6β1 were weakly expressed on both luminal and abluminal surfaces of glomerular endothelial cells; α2β1 and α3β1 were also found on the mesangium of the juxtacapillary areas, α3β1 was regularly present in great density on the basal and lateral surface of podocyte foot processes, confirming α3β1 as the unique β1 integrin on glomerular epithelial cells. None of these integrins was strictly polarized along the glomerular basement membrane, thus suggesting, in agreement with recent literature, that these molecules perform other biological functions in addi