ACE2 and COVID-19: The top cluster in Figure 4A are samples that show weaker innate immune response, including A549, NHBE, Caco2 infected with SARS-CoV-2, H1299 cells infected with SARS-CoV and SARS-CoV-2, and A549-ACE2 cells infected with SARS-CoV-2 at lower MOI (0.2), MRC5 cells infected with SARS, MRC5 and Vero E6 cells infected with MERS, and three PBMC samples of COVID-19 patients.