Based on publicly available datasets from NCBI Gene Expression Omnibus (GSE2658 and GSE5900), we found that G6PD mRNA expression was significantly increased during MM progression from normal bone marrow plasma cells (NP, n = 22), and in “premalignant” individuals with monoclonal gammopathy of undetermined significance (MGUS, n = 44) to malignant plasma cells of newly diagnosed MM (MM, n = 351) (Fig. 1f). This evidence concerns the gene G6PD and monoclonal gammopathy.