CD69 and neoplasm: Consistently, re‐stimulation with 4T1 antigen significantly increased the ratios of IFN‐γ+CD8+ and CD69+CD8+ T cells of BG/Ag@EcN‐treated group compared with those of the naïve mice, confirming that BG/Ag@EcN treatment might generate long‐term immune memory to inhibit tumor recurrence after surgical tumor resection.