The B16F10 melanoma cells (obtained from ATCC) and the DHD/K12/TRb colorectal cancer cells (obtained from Sigma) were cultured in DMEM (GIBCO, France) supplemented with 10% heat-inactivated fetal calf serum (FCS, GIBCO) at 37°C under a humidified atmosphere containing 5% CO2. Cells were passaged by using 0.05% trypsin. Both cell lines were transfected with pcDNA3.1-mNIS (murine NIS)36 (link) using the FuGENE 6 reagent (Roche) according to the manufacturer’s instructions. Stable clones were selected by addition of 1 mg/mL geneticin (G418) to the medium 3 days after transfection. One clone with high functional expression of NIS was selected for each cell line.37 (link)