Fig. 1

Detection of serum exosomes and analysis of exosomal circRNAs. A The size and morphology of serum exosomes detected by TEM. B CD63, TSG101 and calnexin protein expression was evaluated via WB. C The size and concentration of serum exosomes. D A total of 1265 upregulated circRNAs and 787 downregulated circRNAs were identified in MM patients compared with HCs. Red indicates upregulation, and green indicates downregulation. E Volcano plot showing the profile of differentially expressed exo-circRNAs in MM patients vs HCs. F Differential expression of exo-circRNAs in MM patients compared with HCs indicated by the volcano plot. F Among 2052 significantly differentially expressed circRNAs (fold change > 2, P value < 0.05), only 604 circRNAs were known, and 1448 circRNAs were novel. G Distribution of the 2052 circRNAs based on the predicted sequence length. H The 2052 circRNAs were distributed on 22 autosomes, sex chromosomes (X, Y) and mitochondrial chromosomes (M). I The circRNA categories to which each of the 2052 circRNAs belongs