In mice with early-stage breast cancer expressing the HER2 oncogene, dormant tumor cells located in the mammary tissue, lungs, and liver, among other distant organs, can be targeted and suppressed by allogeneic CAR-T cells directed against the HER2 protein, thus maintaining their dormant state and preventing local and distant recurrence of the disease.96 Although preclinical experiments have been conducted using CAR-T-cell therapy to prevent dormant recurrence, its application in dormant tumor cells still lacks corresponding research. This evidence concerns the gene ERBB2 and breast cancer.