The univariate analyses showed that the variables age, BMI, creatinine clearance and CRP, as well as the endothelial biomarkers EMPs, CFU-ECs, CD34+ PCs, CD34+CD45− EPCs, VEGF, endothelin-1 and s-Fractalkine, were different between healthy control subjects and patients with SSc (P < 0.05) (Table 3). Here, PTPRC is linked to systemic sclerosis.