NRP1 and infection: Here, we have demonstrated that our cell line on-chip model expresses key host cell factors for viral infection (ACE2, TMPRSS2, Furin and NRP1) (Hoffmann et al., 2020a; Hoffmann et al., 2020b; Kyrou et al., 2021) after 7 days of culture (Figure 3E), underlining the potential for the AXiAECs on-chip model as a tool to investigate key pathways for productive infection with SARS-CoV-2.