Zhang ZY, et al. - Whether serum exosomal microRNAs can serve as novel serum biomarkers for smouldering myeloma or even multiple myeloma, was investigated in this study including healthy individuals and 20 patients with smouldering myeloma and 20 patients with multiple myeloma. Among patients with multiple myeloma, smouldering myeloma (SMM) and in healthy individuals, significantly different levels of serum exosome-derived miR-20a-5p, miR-103a-3p, and miR-4505 were found, while patients with MM had levels of let-7c-5p, miR-185-5p and miR-4741 different than those in SMM patients or healthy controls. Overall, it is valid to use serum exosomal microRNAs as independent novel serum biomarkers for MM.