Abstract: The present invention in the field of biochemistry and medicine is directed to novel methods for identifying molecules, typically proteins, that move to the cell surface when cells are stimulated or stressed can act as receptors even thought they are not transmembrane molecules and normally originate in the cytosol. Such molecules are useful targets for development of agents that can image or treat tumors or other pathologies. Methods to detect or identify such proteins that have translocated to the cell surface when cells are stressed by an angiogenic environment, environmental stresses, the stimulation of cell proliferation and differentiation, or after exposure to certain drugs such as cancer chemotherapeutics, are disclosed.