Radiolabelling fructose at the C1 position to generate 1-[18F]-FDF (81) has revealed that uptake can be observed in the kidneys and liver, however rapid clearance and a lack of retention was observed.203 6-[18F]-FDF (80) was subsequently synthesised to study imaging in breast cancer in 2009.204 This study noted that administration of the tracer led to inhibition of fructose and d-glucose transport, suggesting interaction with GLUT2 and potentially GLUT5. The gene discussed is SLC2A5; the disease is breast cancer.