Membranous nephropathy (MN) belongs to a family of kidney diseases that is associated with inflammation and hypersensitivity of the glomeruli (glomerulitis) and/or interstitium (nephritis) of the kidney. This is in contrast to tubulopathies, where mainly the renal tubules are affected. The characteristic hallmark of MN is a subepithelial in situ deposition of immune complexes at the glomerular basement membrane (GBM) [1]. Since the thickened GBM can be seen by light microscopy in later stages of illness, this disease was initially termed “membranous glomerulonephritis” [2].