PF4 and systemic sclerosis: Early active SSc (eaSSc, disease duration less than 4 years) either limited/diffuse (N = 19, Supplementary Fig. 1a, and N = 14, Supplementary Fig. 1b), had the highest absolute level of CXCL4, as compared with long-lasting diffuse SSc (dSSc) (P = 0.011; N = 21 and P = 0.0018, N = 38) or limited SSc (lSSc) (N = 36, P = 0.0013) (Supplementary Fig. 1a, b).