TFs play a key role in gene regulation as well as RNA silencing, while miRNAs are also important in the development of diseases.[44] In this study, we found that the TFs associated with key genes are E2F1, E2F3, RBL1, BRCA1, PTTG1, MYC, AHR, E2F4, YBX1, RB1, TP53, EZH2, EP300, ESR1, YY1, and SP1, and all of the above TFs have some connection with COVID-19 and BD. This evidence concerns the gene E2F1 and COVID-19.