SU-DHL-4/RFP cells are derived from the human diffuse large B-cell lymphoma (DLBCL) cell line SU-DHL-4 by stably integration of a constitutive RFP stably expression construct. SU-DHL-4 cell line exhibits the typical properties of DLBCL cells, including rapid growth and the ability to form tumors in vivo. It can serve as a model for studying various aspects of lymphoma biology and testing the efficacy of new therapeutic agents. SU-DHL-4/RFP cells stably express RFP, can be used for in vitro assays and in vivo imaging.