GZMB and viral infectious disease: Overall, in the Healthy group, the minor clones were immune surveillance cells and maintained homeostasis of immune response (Fig. 7a); in the Discharged group, most low expanded minor clones were defensing against virus infection (IFN-related) and cytotoxic (granzyme) clones (Fig. 7b); and the Follow-up group possessed GZMB-cytotoxic clones and the major metabolic clones (Fig. 7c).