The reason why no correlation emerged between glomerular ClC-5 expression, at mRNA or protein level, and proteinuria in all the proteinuric nephropathies we studied (NIDDM, IgAN, MG) might lie in the fact that not all our patients underwent ACE inhibitor therapy wash-out, and in the small number of patients considered in this study. This evidence concerns the gene ACE and type 2 diabetes mellitus.