TSLPR-specific CAR. (A) A schematic diagram of a CAR expressed at the T-cell surface, illustrating the typical component parts found in a second-generation variant. (B) Cartoon depicting the elimination of B-ALL target cells with a CRLF2 rearrangement by TSLPR-retargeted CAR T cells. By contrast, healthy B-lymphocyte precursors (hematogones) express TSLPR at low levels, which may protect them from immune attack. Some epithelial cell types also express low levels of TSLPR, although immunohistochemical analysis suggests that the target is not present at the cell surface.