ACE2 and COVID-19: Weight loss, virus replication, viral antigens, and interstitial pneumonia were observed in hACE2 mice after SARS-CoV-2 infection, while these phenomena were not found in wild-type mice infected with SARS-CoV-2.158 In addition, the Shi Zheng-Li’s group developed a mouse model with symptoms similar to those of patients with COVID-19 by transgenic technology (HFH4-hACE2 in C3B6 mice).159 In the HFH4-hACE2 COVID-19 model, HFH4was used to control human ACE2 expression.