The concept of cancer immunotherapy is based on the existence of tumor-associated antigens against which the host is capable of mounting an immune response leading to tumor rejection. One of the challenges in this field is the discovery of appropriate targets. Viventia has developed an integrated approach for the discovery and identification of such tumor-specific targets using antibodies generated by a patient’s immune response to their malignancy. To navigate the diverse array of membrane antigens that represent targetable molecules for immunotherapy, Viventia has developed a proteomics-driven platform based upon leading edge protein identification and characterization tools. Our approach of using the immune system’s response to cancer as a target discovery tool enables Viventia to have at its disposal potentially the entire spectrum of cancer specific drug targets that exist on the surface of cancer cells. When promising antibody candidate reaches the advanced stages of ImmunoMine™ screening, Viventia begins a parallel process of target identification and characterization for that antibody. The systematic approach for the identification of antigens, coupled to our Fusogenics™ and ImmunoMine™ platforms, afford a novel discovery and screening opportunity for the identification of new tumor-associated antigens, in step with therapeutic drug development.