CLEC4M and infection: To demonstrate that L-SIGN is a receptor for authentic SARS-CoV-2 virus, we infected L-SIGN-flag–expressing or –nonexpressing LSECs with authentic SARS-CoV-2 virus with multiplicity of infection (MOI) of 1 (MOI refers to the number of viruses that are added per cell during infection) for 18 hours and observed L-SIGN–dependent authentic SARS-CoV-2 infection in LSECs at 48 hours after infection (Figure 5, D–F).