MUC20 and monoclonal gammopathy: Analysis of the GEO data demonstrated that MUC20 expression in CD138 + bone marrow plasma cells was consistent among healthy donors (HDs) (GSE5900) and patients with monoclonal gammopathy of undetermined significance (MGUS) MM (GSE5900), smoldering MM (SMM) (GSE5900), and newly diagnosed MM (NDMM) (GSE16791) (Fig. 1D).