PLA2R1 and membranous glomerulonephritis: Identified in more than 70% of the cases of IMN, PLA2R has been considered the main antigen in membranous nephropathy, although it is often absent in secondary forms of the disease and other forms of glomerulopathy.3-5 Antibodies against THSD7A have been observed in approximately 10% of the PLA2R-negative patients with IMN.