COVID-19(10) coronavirus disease(5) Analysis(5) patients hospitalized(5) Patient(5) Frequency(4) investigated(4) statistical analysis(4) other variant(4) ACE2(4) knowledge(4) ACE1(4) polymorphism(4) frequencies(4) Peripheral blood(4) single-center(4) Genotype(4) Sequencing analysis(4) Admission(4) radiologic(4) determine(4) I/D polymorphism(4) independent predictor(4) Clinical characteristics(4) variant(4) no effect(4) cohort study(4) domain(4) Sanger sequencing(4) Genomic DNA(4)