Some practical examples of mAbs recognizing cancer specific biomarkers that are approved by the FDA and/or EMA and are currently used in the clinical setting are shown in Table 2A. Among these, ProstaScint is a mAb used in prostate cancer patients as a diagnostic imaging agent to detect nodal metastases “pre-prostatectomy”, or recurrence in post prostatectomy patients with a rising prostate-specific antigen (PSA). The gene discussed is KLK3; the disease is cancer.