CD4 and B-cell chronic lymphocytic leukemia: Our data support this notion by showing (i) antigen-specific activation of CXCR5 CAR-T cells in co-cultures with human CXCR5+CD4+ peripheral blood T cells, (ii) complete depletion of cTfh cells in FL and CLL samples from peripheral blood by co-cultures with CXCR5 but not with CD19 CAR-T cells, and (iii) efficient depletion of follicular CXCR5+CD4+ T cells in the spleen of mice treated with anti-murine CXCR5 CAR-T cells.