Anti-CCR9 CAR T cells for T-ALL. (A) A major challenge for the adoption of CAR T-cell therapy for T-ALL is the inability to find T-ALL–specific antigens that are not expressed on normal T cells. Targeting common T-cell antigens would lead to T-cell fratricide and a profound immunosuppression. (B) Maciocia et al report the identification of CCR9, a chemokine receptor expressed on a small subset of normal T cells, as a promising target for T-ALL–directed CAR T-cell therapy. Schematic was created with Biorender.