HSPA9 and COVID-19: As CsA and Cepharanthine are approved drugs that have been used in the clinic for decades, and their safety and pharmacokinetics have been extensively evaluated (e.g., the reported Cmax values of CsA and Cepharanthine in human serum or mice brain ranged from 6.9 to 300 μM, which were much higher than the IC50 values observed in our study),51–53 our promising in vivo results warrant the continued development of Cepharanthine and CsA as potential COVID-19 therapies.