KDR and systemic sclerosis: Both are markers of vascular injury and were described earlier to be elevated in LcSSc PAH patients.32 Our research group recently described several soluble markers including VEGFD that could possibly discriminate pathophysiological different phenotypes in SSc.33 Possibly angiogenesis, or a disturbance of this process in SSc-PH, could also be reflected by the ratio between VEGFD and VEGFR2, which could be an interesting observation to explore in future studies.