We designed an alternative engager molecule (Anti-TRGV9/anti-CD123), a bispecific antibody that can simultaneously bind to the Vγ9 chain of the Vγ9Vδ2+ γδ T cell receptor and to AML target antigen, CD123, to selectively recruit Vγ9+ γδ T cells rather than pan T cells to target AML blasts. The gene discussed is TRGV9; the disease is acute myeloid leukemia.