PROS1 and COVID-19: However, much research is needed to know the status of ACE2 expression in various tissues of COVID-19 patients after the administration of such inhibitors in COVID-19 (Li et al. 2020a; b). Chloroquine is reported to interrupt the interaction between viral S protein and ACE2 by inhibiting the glycosylation of ACE2 (Fantini et al. 2020). Further, drug-repurposing strategies have been suggested to find possible molecule that may bind to S-protein to disrupt S protein-ACE2 interaction (Letko et al. 2020).