The CAR-MAIT cell TCR identifies high levels of MR1 molecules on myeloid-cell-derived APCs, which have been found to exacerbate acute and chronic donor T-cell-induced GvHD; hence, CAR-MAIT cells may remove these myeloid APCs and diminish GvHD [48,54,55]. This evidence concerns the gene MR1 and graft versus host disease.