Remarkably, the correlation between the intensity of the anti-CXCL4 antibody response and IFN-α in plasma was present in the early diffuse group (r = 0.66, p = 0.03, n = 9) and in the long-lasting SSc group (Spearman’s r = 0.59, p = 0.037, n = 10). Here, PF4 is linked to systemic sclerosis.