Patients with SSc (SSc all and lSSc) showed significantly higher percentages of CD31+ cells as compared to healthy controls whereas dSSc patients did not: Controls 72 ± 12 %; SSc all 94 ± 1.9 %; lSSc 95 ± 1.3 %; dSSc 92 ± 4.6 %; the p-values were: Controls vs. SSc all p = 0.01; Controls vs. lSSc p = 0.03; Controls vs. dSSc p = 0.18 (Fig. 2). This evidence concerns the gene PECAM1 and systemic sclerosis.