TOP2A and COVID-19: This study has identified 1) potential therapeutic targets, including CCNA2, CCNB2, AURKB, TOP2A, and BIRC5; 2) signaling pathways primarily related to cell cycle, cell aging, viral carcinogenesis, and p53 signaling pathway; 3) potential agents for the treatment of COVID-19 and NSCLC, including quercetin, resveratrol, cyclosporine, dasatinib, etoposide, ascorbic acid, and decitabine.