Peak CD19 CAR T-cell expansion comparison between the initial and second CAR T-cell infusion among 10 patients who had CAR T-cell retreatment. There was no significant difference between median peak CAR T-cell expansion between the first and second CAR T-cell infusion. Each solid line links the peak vcn/mL of CAR T cells of each individual patient at the first and second infusion. The top and the bottom of the boxplots reflect the interquartile ranges of CAR T-cell expansion. The thick line in each boxplot represents the median of peak CAR T-cell expansion.