Abstract: Provided herein are methods comprising multifunctional binding proteins comprising a first and a second antigen binding domain and all or part of an immunoglobulin Fc region or variant thereof, wherein the first antigen binding domain binds specifically to CD123 and the second antigen binding domain binds specifically to human NKp46, and wherein all or part of the immunoglobulin Fc region or variant thereof bind to a human Fc-? receptor, for the treatment or prevention of leukemias and myelodysplastic disorders.