CD9 and type 2 diabetes mellitus: According to the electron microscopy (Fig. 5A), DLS (Fig. 5B) and western blotting results (Fig. 5C), we obtained round morphology exosomes with a mean size of 107 nm in control subjects, 128 nm in T2DM patients and 90 nm in DKD patients with positive expression of CD9, CD63 and CD81 and negative expression of GM130 and ApoB, which is consistent with previous reports [10, 11].