U266/Luciferase cells are derived from the human myeloma U266 cell line by stably integration of a constitutive Firefly luciferase expression construct. U266 cell line has been widely used in cancer research and drug development. U266/Luciferase cells express Firefly luciferase under the control of the CMV promoter, can be used for in vitro assays and in vivo imaging.