To specifically compare local CD8+ TRM cell-mediated immunity between mice harboring tissue-resident OT-I Rgs1+/+ and OT-I Rgs1-/- TRM cells in the small intestine, the circulating CD8+ T cells, including circulating OT-I Rgs1+/+ and OT-I Rgs1-/- memory cells, were depleted by injecting the mice with anti-CD8α mAb (450μg/animal, i.p.)before the secondary infection (59). The gene discussed is CD8A; the disease is infection.