Fig 1: Enrichment of CAR T cells in the patients’ CSF. Analysis of BCMA-targeted CAR T cell numbers in the PB and the CSF after CART infusion. Analyses were performed by flow cytometry following staining with BCMA CAR detection reagent (Miltenyi, Cat# 130-133-888), which represents a fluorescent, full-length, recombinant BCMA protein binding to the CAR expressed on the cell surface, and co-staining with anti-CD3 and other T cell markers. Dot plots (two upper rows) show percentages of CAR-expressing T cells vs. all T cells in the patient’s PB (upper row) and CSF (middle row), respectively, at different timepoints. To control for unspecific background staining a Fluorescence Minus One (FMO) control was used (lower row).