HA ET AL. the secretion of VEGFA by these cells. Whereas we found that monocyte-derived dendritic cells secreted TGFB1 in response to PSG1 treatment, VEGFA secretion was not induced. Recent reports indicate that uterine dendritic cells fine-tune decidual angiogenesis by producing TGFB1 and secreted FLT1 and that they have an important role in vascular development [49, 54] . Interestingly, only alternative activation-not TGFB1 treatment-was reported to lead to VEGFA production by dendritic cells [55] . Therefore, it remains to be investigated whether, in the decidual microenvironment, PSG1 may induce dendritic cells to secrete VEGFA.