Similarly, CD63 levels were higher in SLE exosomes (n = 9) than HC exosomes (n = 6) (median (IQR), μL: 40.15 × 107 (28.41 × 107–55.29 × 107) vs. 24.45 × 107 (18.29 × 107–41.30 × 107), respectively; p = 0.013) (Fig. 1d). Here, CD63 is linked to systemic lupus erythematosus.