F2R and acute respiratory distress syndrome: This PAR1 activation also activates cells, resulting in P- and E-selectin exposure.83One can imagine that in the case of a patient with preexisting lung disease, such as idiopathic fibrosis or asthma, where there is already an increase in FX expression and activation, along with increased PAR1 activation and fibroblasts, and that this would create a naturally hospitable environment for the binding of SARS-CoV-2, increasing cell infection and the development of severe lung pathology, such as ARDS (Fig. 2A).