Whole-body PET/CT imaging of normal volunteers revealed a high accumulation of [18F]VM4-037 in the kidney and liver, with uptake doses of 273 ± 31 and 240 ± 68 μGy/MBq, respectively, making it unsuitable for imaging CA IX upregulation in these two organs.190 A phase II pilot study of [18F]VM4-037 further demonstrated that it is difficult to visualize primary ccRCC lesions because of the significant uptake in healthy kidney tissue. The gene discussed is CA9; the disease is nonpapillary renal cell carcinoma.