Since CXCL4 is a DNA/RNA binding protein, and knowing that circulating CXCL4–DNA complexes can activate pDCs to produce IFN-α [12] and possibly become the targets of anti-CXCL4 antibodies, we wondered whether the presence of anti-CXCL4 antibodies in SSc blood showed any relationship with blood IFN-α level. The gene discussed is PF4; the disease is systemic sclerosis.