Complexes suitable for targeting and killing a human target cell comprising a first polypeptide with a binding structure for binding the complex to the cellular surface receptor CD89 (e.g. with an anti CD89 antibody) presented on the cell surface of the human target cell and a second polypeptide comprising a toxic effector domain, preferably Pseudomonas exotoxin A)； to nucleic acid molecules encoding said complexes, vectors, host cells containing the nucleic acids and methods for preparation and producing such complexes； compositions and methods for using said complexes for the treatment of diseases, in particular of cancer diseases like leukemia.
