In a total of 55 patients with biopsy-proven MCD and 26 patients with biopsy-proven idiopathic membranous nephropathy, CD80 and cytotoxic T-lymphocyte antigen-4 (CTLA-4) levels in serum, urine and renal tissue were analyzed. This evidence concerns the gene CD80 and idiopathic membranous glomerulonephritis.