A method of selecting a target for treatment of a hyperproliferative disease in a subject in need thereof is disclosed. The method comprising analyzing an amount and/or activity of at least one ErbB ligand in a biological sample from the subject, wherein an ErbB ligand which shows an up-regulated amount and/or activity compared to a non-hyperproliferative cell or tissue above a predetermined level is selected as a target for treatment of the hyperproliferative disease. Methods of treating hyperproliferative diseases, monoclonal antibodies and pharmaceutical compositions are also disclosed.
