CAR19-22 expansion and persistence. Shown are CAR19-22 levels (medians with interquartile ranges) in the peripheral blood in the first month after CAR infusion as measured by (A) quantitative PCR and (B) CARFACS. NKTR-255 administration is denoted by the red dashed line. The number of observations at each time point is shown below the graph. (C) CD4 and (D) CD8 CAR subsets assessed by CARFACS. (E) CD4:CD8 CAR⁺ ratio during the first month after CAR19-22. (F) ALC (circles) and total CD3⁺ T cells by CARFACS (triangles).