As evidenced by longitudinal monitoring (Figs. 4C and 5B), the HER2-CXCR5-CCR6-CAR T group maintained significantly higher peripheral CAR T cell frequencies (32.2% vs. ≤ 12.3% in single-receptor groups at Day 42), which directly paralleled superior tumor suppression (14,600 ± 5,313.67 p/s vs. ≥ 45,520 p/s in controls). This evidence concerns the gene CCR6 and neoplasm.