Providing antigen-expressing cells to CAR T cells may improve CAR T-cell engraftment. CAR T-cell immunotherapy involves transducing T cells with a CAR that enables T cells to specifically target and kill cells expressing a particular antigen. In situations in which antigen is in low abundance (such as HIV infection in which antigen is suppressed by antiviral drug therapy), CAR T cells can be helped by infusing cells that express the antigen for which the CAR is specific, that is, HIV Env. Professional illustration by Somersault18:24.