Taking pre-transplant MMP3 levels of VCA patients as a reference (median 7.73 ng/mL, IQR: 4.25–11.95 ng/mL), we found higher levels of MMP3 in HC (median 16.9 ng/mL, IQR: 13.04–21.83 ng/mL, p = 0.003) and patients with SLE (median 21.05 ng/mL, IQR: 10.71–48.07 ng/mL, p = 0.006), but not in other patients with autoimmune skin disease (Figure 3). Here, MMP3 is linked to systemic lupus erythematosus.