Membranous nephropathy (MN) is a primary cause of nephrotic syndrome in adults, characterized by the formation of immune complexes on the podocyte side of the glomerular basement membrane. Despite the identification of several target antigens (such as PLA2R and THSD7A), the underlying pathophysiology of MN remains incompletely understood. Recent advances in liquid chromatography–mass spectrometry (LC-MS) technology have enabled more comprehensive proteomic analyses, providing opportunities to discover novel disease-associated proteins. Identifying these proteins may enhance our understanding of MN pathogenesis and offer new diagnostic and therapeutic targets.