In addition, pDCs from SSc patients secrete high levels of Chemokine (C-X-C Motif) Ligand 4 (CXCL4), and the increased amount of circulating CXCL4 correlates with the extent of skin fibrosis, as measured by the modified Rodman skin score (mRSS), and lung fibrosis [5]. Here, PF4 is linked to pulmonary fibrosis.