Membranous Nephropathy, or Membranous Glomerulopathy, is an autoimmune disease-causing nephrotic syndrome in which there is subepithelial deposition of IgG and complements along the glomerular basement membrane. Membranous Nephropathy is the second leading cause of nephrotic syndrome in adults. Following the description of the first membranous antigen PLA2R in 2009, there has been numerous antigens described and associations with different diseases. In addition to a discussion of the individual antigens, this review article covers a description of techniques for discovery of new antigens and how these techniques have changed over time.