During the initiation and propagation stages of infection, several renin-angiotensin system (RAS) family genes (e.g., ACE2 and ANPEP) are upregulated, whereas others (e.g., epidermal growth factor receptor - EGFR and insulin-like growth factor 2 receptor - IGF2R) are downregulated [6,7]. The gene discussed is ACE2; the disease is infection.