Association of PSI with OR and treatment-related adverse events. Single-cell product PSI was determined for 20 patient donors by using SCBC proteomic analysis of a panel of 32 secreted cytokines, chemokines, and cytotoxic molecules. Of the 20 patients, 14 had an OR to the CAR T-cell therapy. The products were ranked according to CAR T-cell PSI levels, and the PSI was associated with the OR (A,C) or grade ≥3 CRS (B,D) as indicated. The results are shown as patient-level PSI (A-B) and mean ± standard error PSI (C-D). All statistical values were computed using the Mann Whitney U test.