This assay is helpful to assess changes and proportions of various proteins, particularly the M-protein, in a known case of Monoclonal gammopathy. It helps to track the progression of Myeloma and the response to treatment. The level of β2-microglobulin reflects the tumor mass and is considered as a standard measure of the tumor burden. In addition, the FLC ratio is required for documenting stringent complete response according to the International Myeloma Working Group Uniform Response Criteria.