In vitro and in vivo studies demonstrated that the Rk3/Met URS MNs effectively regulate the four hallmark pathological features of SSc, including immune dysregulation, inflammation, vascular abnormality, and aberrant fibrosis, by down-regulating ACA, TNF-α, IL-6, Col I, and α-SMA while simultaneously up-regulating CD31. The gene discussed is PECAM1; the disease is systemic sclerosis.