Baseline CXCL4 levels (ng/ml) were higher in SLS II participants (N = 136) compared with healthy controls (N = 67) (SSc: mean 2699 (SD 1489), median 2480 (IR 1585, 3889); controls: mean 2233 (SD 1351), median 1720 (IR 1224, 2874); P = 0.019) (Fig. 1). Here, PF4 is linked to systemic sclerosis.