Recently, the IKMG expanded the definition of MGRS to encompass all B-cell or plasma cell proliferative disorders that generate a kidney-damaging M-protein, including conditions like smoldering multiple myeloma (MM), smoldering Waldenström’s macroglobulinemia (WM), and monoclonal B-cell lymphocytosis (MBL). Here, MYOM2 is linked to plasma cell myeloma.