PLA2R1 (phospholipase A2 receptor 1) is a transmembrane receptor that serves as the primary target antigen in autoimmune membranous nephropathy, one of the leading causes of nephrotic syndrome in adults 1. The protein functions as a receptor for secretory phospholipase A2 and is predominantly expressed on podocyte surfaces in the kidney glomerulus 2. In primary membranous nephropathy, circulating IgG4 autoantibodies against PLA2R1 are detected in 50-80% of patients, representing a major breakthrough in understanding disease pathogenesis 34. These anti-PLA2R antibodies are pathogenic, forming immune complexes that deposit along the glomerular basement membrane and cause characteristic subepithelial deposits 5. Antibody levels correlate with disease severity and serve as valuable biomarkers for diagnosis, monitoring disease progression, and assessing treatment response 6. The presence of anti-PLA2R antibodies has transformed membranous nephropathy from an idiopathic condition to a recognized autoimmune disease with precision-based diagnostic and therapeutic approaches 4. High specificity of PLA2R antibodies may even eliminate the need for kidney biopsy in certain nephrotic syndrome cases 4. This autoimmune mechanism represents approximately 70% of primary membranous nephropathy cases, with other antigens like THSD7A and NELL-1 accounting for smaller subsets 7.