(a) Schema of the high tumor burden SH-SY5Y metastatic xenograft NB model using NSG mice inoculated via tail vein injection with FFLuc-SH-SY5Y cells (1 × 106 cell/mouse) and treated 7 days later with CD19.28ζ, GD2.28ζ or GD2.28ζ/B7-H3BB CAR-T cells (1 × 107 cells/mouse) intravenously. (b,c) Representative tumor bioluminescence (BLI) images (b), and tumor BLI kinetics (c) of FFLuc-SH-SY5Y tumor growth (n = 5 mice/group) in the metastatic xenograft NB models shown in (a). (d) Kaplan-Meier survival curve of mice in (B,C), n = 5 mice/group, comparisons of survival curves were determined by Log-rank test, **p = 0.0023 for CD19.28ζ vs. GD2.28ζ, **p = 0.0027 for GD2.28ζ vs. GD2.28ζ/B7-H3.BB.