mSlc5a5 Overexpression Stable Cell Line-4T1 is a polyclonal population which is constructed by lentivirus transduction, followed by stable cell selection. This cell line stably expresses mouse Slc5a5 cDNA driven by spleen focus-forming virus (SFFV) promoter and puromycin resistance gene driven by PGK promoter. It is an ideal positive control for use in iodine uptake assays. In addition, 4T1 cells form tumors post implantation into immunocompromised mice. The in vivo growth of these tumors can be monitored using PET/SPECT imaging.