One aspect of the invention provides a method for treating a cancer including administering to a subject in need of such treatment a composition including a therapeutically effective amount of an antibody directed against p40 monomer or an immunologically active fragment thereof. In various embodiments, the antibody is a polyclonal, monoclonal, human, humanized, and chimeric antibody； a single chain antibody or an epitope-binding antibody fragment. In other embodiments, the cancer is, for ex ample, prostate cancer, breast cancer or liver cancer.
