PROS1 and Venous thrombosis: In conclusion, our results revealed that in placental cells, SARS-CoV-2 S-protein induces release of pro-inflammatory cytokines and chemokines, which likely contributes to the “cytokine storm” in pregnant women and potential cause of placental dysfunction as well as elevated F3 levels that may trigger the vascular thrombosis seen in the placentas of women infected with COVID-19.