Since AXL is not co-expressed with ACE2 in human lungs or trachea, it appears that AXL acts as an ACE2-independent receptor for SARS-CoV-2 infection.115 To establish the animal infection model and solve the molecular structure of NTD-AXL interaction would further promote our understanding of viral entry and provide clues for therapeutic interventions. Here, ACE2 is linked to infection.