CCR5 and COVID-19: Leronlimab, a humanised monoclonal antibody (CCR5 antagonist) arbidol hydrochloride combined with interferon atomisation, lopinavir plus ritonavir, ritonavir plus oseltamivir, ASC09F plus oseltamivir, mesenchymal stem cell treatment could also be a choice for the treatment of COVID-19 patients.