COVID-19(11) drug(7) expression(7) Patient(6) Treatment(6) risk(6) Mitochondria(5) copy number(5) nucleoside(5) antiviral drugs(5) molecular(5) functional(5) Genome(5) Toxicity(5) antiviral drug(5) HepG2(5) RNA polymerase(5) mitochondrial(5) cytotoxicity(5) approved(5) mechanism(5) Culture(5) Concentration(5) flux(4) concentrations(4) Replication(4) resulting(4) metabolite(4) SARS-CoV-2(4) emergency treatment(4)