Because ACE2-Ig-105/106 has better in vitro neutralization potency but shorter plasma half-life than ACE2-Ig-95, we then performed a pilot experiment using an adenovirus type 5 (Ad5)-hACE2-sensitized COVID-19 mouse model to compare i.p. administration with intranasal (i.n.)administration of the two proteins for the treatment of SARS-CoV-2 infection (33) (Fig. 3G). The gene discussed is ACE2; the disease is COVID-19.