RFP Reporter Cell Line-HT1080 is a polyclonal population which is constructed by lentivirus transduction, followed by stable cell selection. This cell line stably expresses RFP and puromycin driven by the spleen focus-forming virus (SFFV) promoter. It is an ideal positive control for use in fluorescence assays. In addition, HT1080 cells form tumors post implantation into immunocompromised mice. The in vivo growth of these tumors can be monitored using optical imaging.