KLRK1 and graft versus host disease: Current versions of the NKG2D-CAR constructs can also contain TCR Inhibitory Molecule (TIM), a small peptide which is capable of interfering with endogenous TCR signaling thought to contribute GvHD (Fig. 1B middle) [20], or an short-hairpin RNA (shRNA) which targets NKG2D ligands MICA and MICB that can be naturally present on T cells, effectively preventing fratricide (Fig. 1B bottom) [21].