For example, when the S protein alone is ectopically expressed in human cells, it induces pro-inflammatory responses in the host cells [9,10,11,12], causes endothelial cell damage, and disrupts the blood–brain barrier function [13], indicating that aside from its well-known canonical role in viral entry, SARS-CoV-2-S protein could play a direct role in the pathogenesis of COVID-19. Here, PROS1 is linked to COVID-19.