GZMB and infection: Therefore, the protection induced by LmCen-/- against infection with virulent L. major parasites might be, in part, due to rapid recruitment, proliferation, and induction of Th1 response and cytotoxic response (Granzyme B) by CD4+ TRM cells at the site of infection in addition to the IFNγ-secreting CD4+ T effector cells and multifunctional T cells (8).