A better understanding of the molecules that control the process of angiogenesis and trophoblast-mediated vascular remodeling during pregnancy is important, because disturbanc-es in placental blood flow and vascular development impair fetal growth [21] . Angiogenesis occurs at all stages during pregnancy to ensure that the embryo will be supplied with sufficient nutrients and oxygen [22, 23] . The results presented here suggest that PSGs could contribute to the process of establishing the maternal-fetal vasculature in two ways. First, PSG1 has the ability to induce TGFB1 and VEGFA by different cell types, including monocytes/macrophages and extravillous trophoblasts. Second, PSG1 has the capacity to interact with endothelial cells, inducing tube formation, as well as to enhance vascular morphogenetic processes induced by VEGFA.