FACS analysis showed that at T0 the percentage of fibrocytes, identified as CD45+COL I+CXCR4+ cells, was 1.0 ± 1.2% in SSc patients and 0.5 ± 0.2% in HSs (50% less) (Fig. 1a). The gene discussed is CXCR4; the disease is systemic sclerosis.