PAPOLG and COVID-19: Figures 5A, B show that the expression level of most 3’ processing factors was significantly higher in COVID-19 patients (P < 0.05), especially CPSF2, PAPOLG, FIP1L1, and PCF11. To validate our results, we analyzed RNA-Seq data from other independent COVID-19 datasets and observed the same results (Figure S4B), suggesting change of APA is associated with expression level of 3’processing factors in COVID-19 patients.