MM.1S/RFP-Luciferase cells are derived from the human B lymphoblast MM.1S cell line by stably integration of a constitutive RFP-Firefly luciferase stably expression construct. MM.1S cells have been used in to study multiple myeloma progression, and test the new drugs or treatment strategies for multiple myeloma. MM.1R and MM.1S, were independently created from the parental cell line MM.1 to represent models of resistance and sensitivity, respectively, to dexamethasone. MM.1S/RFP-Luciferase cells stably stably express RFP and Firefly luciferase, can be used for in vitro assays and in vivo imaging.