The ACE2 untransduced cell lines exhibited basal levels of NLuc expression, as can be seen with NCI-H23, HEK293T, and A549 cells (Figure 3D), and the ACE2 transduced cell pools and monoclonal cell lines exhibited an increase in the NLuc expression from 0–72 h post-infection (Figure 3D), thus confirming that the cell lines successfully support virus replication. The gene discussed is ACE2; the disease is infection.