The core gene map in Fig. 3b shows that the top-ranking genes were IL6, MAPK3, MAPK8, CASP3, IL10, IL1B, CXCL8, MAPK1, CCL2, IFNG, IL4, etc. These genes were mainly concentrated in the inflammatory response, immune modulation, and cellular stress processes, which indicated that they might play a key role in DYY treatment of COVID-19. Here, IFNG is linked to COVID-19.