IFITM1 and COVID-19: Notably, IFITM3 is among the most highly induced genes in primary human lung epithelial cells exposed to SARS-CoV-2 (83, 84), and patients experiencing mild or moderate COVID-19 showed elevated induction of antiviral genes, including IFITM1 and IFITM3, in airway epithelium compared with individuals with more severe COVID-19 (85).