Abstract: Antibodies, humanized antibodies, resurfaced antibodies, antibody fragments, derivatized antibodies, and conjugates of same with cytotoxic agents, which specifically bind to, and inhibit A class of Eph receptors, antagonize the effects of growth factors on the growth and survival of tumor cells, and which have minimal agonistic activity or are preferentially devoid of agonist activity. Said antibodies and fragments thereof may be used in the treatment of tumors that express elevated levels of A class of Eph receptors, such as breast cancer, colon cancer, lung cancer, ovarian carcinoma, synovial sarcoma and pancreatic cancer, and said derivatized antibodies may be used in the diagnosis and imaging of tumors that express elevated levels of A class of Eph receptors.

Abstract: A monoclonal antibody which specifically binds to an antigen on the membrane of mitochondria in apoptotic cells. The antigen is a 38 kD protein that is detectable in cells undergoing apoptosis and undetectable in normal cells. This selectivity of the monoclonal antibody provides a method of distinguishing between normal and apoptotic cells in a sample of human hemopoietic cell populations. A method for detecting and measuring cells undergoing apoptosis is also provided.