CAR trafficking. CAR dynamics for patients with CNS leukemia. Shown are (A) peripheral blood ALC, (B) CD8⁺ CAR-Ts, and (C) CSF absolute white blood cell count (WBC; circles) and CAR19-22⁺ cells (triangles) for patients treated with NKTR-255 with CNS disease (n = 2). (D) WBC count (circles) and CAR⁺ cells in the CSF on day +28 evaluated by flow cytometry for the same patients treated with NKTR-255 (blue, n = 2) and the historical control patient with evaluable CSF (red, n = 1).