In our present study, unbiased whole-transcriptome sequencing of isolated lung ECs from aged humanized transgenic ACE2 mice showed less induction of adhesive markers (e.g., Icam1) and inflammatory chemokines (e.g., Ccl2), and impaired interferon (IFN) response, and TREM1-signaling compared to young mice at 2 days post infection (2dpi). The gene discussed is CCL2; the disease is infection.