Cells were treated with Rituximab (RTX) 72 hours after lentiviral vector transduction. Cell proliferation was measured 48 hours after Rituximab treatment using (a) Trypan Blue staining and direct cell counting and (b) BrdU assay and flow cytometry analysis. (c) Lack of effect of Doxorubicin as shown by measuring the cell proliferation 48 hours after treatment with the drug. (d) Lentivirus-mediated increase of tolerance to Rituximab in GCB-Like DLBCL cell lines (OCI-Ly-7, SU-DHL-5), but not in ABC-Like cells. (e) Decrease of cell proliferation in OCI-Ly-7 and SU-DHL-5 cells treated with lentiviral vectors. Numbers of cells were determined after 96 hours of incubation. NTC, nontranduced cells; LVTC, lentiviral vector-transduced cells. Asterisks indicate level of significance as follows: *: p value≤0.05, **: p value≤0.01, ***: p value≤0.001.