CD27 and acute myeloid leukemia: The build upon the earlier clinical efficacy of NKG2D CAR therapy in acute myeloid leukemia [7], NKG2D CARs were developed consisting of the extracellular portion of the human NKG2D receptor linked to a CD8a hinge and transmembrane region, followed by a CD3z signaling moiety alone (GFP-NKG2D-z) or in tandem with the 4-1BB (GFP-NKG2D-BBz) or CD27 (GFP-NKG2D-27z) intracellular signaling motif (Fig. 2a).