DEFA4 and viral infectious disease: Several differentially expressed genes between the two trajectories (CTSG, PRC1, DEFA4, KIF15, TCEAL9, HMMR, CEP55, and AZU1) were overexpressed in patients with severe viral infection, but not in those with non-severe viral infection compared to HCs (Figures 5J–5K, Figures S4E and S4F).