A recent example in RCC is carbonic anhydrase IX (CAIX), where PET-CT using zirconium radiotracer conjugated girentuximab (anti-CAIX monoclonal antibody) was found to be 85.5% sensitive and 87% specific for diagnosing clear cell (cc) RCC in a phase 3 trial [8]. The gene discussed is CA9; the disease is renal cell carcinoma.