CD27 and B-cell chronic lymphocytic leukemia: Resistance to CD19-CAR T cells in this cohort of CLL patients was linked to the upregulation of pathways involved in effector differentiation, glycolysis, exhaustion, and apoptosis, while a subset of CD27+ PD-1− CD8+ CAR T cells with high expression of IL-6 receptor was associated with increased therapeutic responses [30].