TMPRSS2 and infection: Unlike other cells, despite Huh-7 is permissive to SARS-CoV-2, co-expression analyses of ACE2 and TMPRSS2 revealed that Huh-7 cells strongly expressed TMPRSS2 but lacked ACE2 expression (Figure 2), which was understood as an indication that each receptor plays an individual role in aiding the infection (Saccon et al., 2021).