GZMB and infection: Here the lower levels of granzyme B observed in children with malaria infection and the upregulation of IL-4 support the immunoregulatory activity of IL-4 on granzyme B. Furthermore, the positive correlation observed between both IL-4 and granzyme B in children with submicroscopic infections may indicate that probably at the sub-patent level of infection, the effect of IL-4 on regulating granzyme B expression is reduced.