FLT4 and systemic sclerosis: Increased VEGFR3/FLT4 transcript levels have instead been revealed in SSc skin biopsies [20], though it should be considered that in pathologic conditions the expression of this receptor is not restricted to the lymphatic endothelium, but is found also in blood vascular endothelial cells and cells of the monocyte/macrophage lineage [37,38,39,40].