In our study, higher levels of serum IFN‐γ were robustly detected in the p.v. CAR‐T treatment group, correlating with better CAR‐T cell infiltration into tumours (Figure 4A), compared to systemic CAR‐T cell delivery via tail vein (Figures 2G, 3G and 5H). This evidence concerns the gene IFNG and neoplasm.