GPC2 and neoplasm: These observed transcriptional changes during early infiltration and expansion in all cell clusters are consistent with the in vivo kinetics of CAR T cell killing, which showed tumor regression to occur first in the GPC2-CAR group as early as 7 days after adoptive cell transfer, while by B7-H3-CAR and GD2-CAR groups have the most pronounced killing around 14 days (Figures 3D).