TriKEs recognizing the NKG2D receptor ligand ULBP2 (ULBP2/aCD19/aCD19 and ULBP2/aCD19/aCD33 TriKEs) have also been used to activate NK cells and showed a superior in vitro and in vivo anti-tumor activity against CLL compared to the bi-specific counterparts (201). This evidence concerns the gene ULBP2 and neoplasm.