KLRK1 and hematologic disorder: For NKG2D binding, such molecules harbor domains derived from natural NKG2D ligands like ULBP2 or MICA [21,22,23,24], or NKG2D-specific single-chain fragment variable (scFv) antibodies or nanobodies [25,26,27,28], which are, in each case, linked to a second binding domain that targets a distinct surface antigen expressed by hematological malignancies or solid tumors.