MM.1R/RFP cells are derived from the human B lymphoblast MM.1R cell line by stably integration of a constitutive RFP stably expression construct. MM.1R cells have been used in to study the molecular and cellular mechanisms that drive multiple myeloma progression, and test the efficacy of 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.1R/RFP cells stably express RFP, can be used for in vitro assays and in vivo imaging.