Interaction between GS-1101 and LBH589 is dose dependent and synergistic. A) GS-1101 and LBH589 synergistically inhibit proliferation/survival of SU-DHL-6/16 cells. Cytotoxicity was determined by WST-1 proliferation assay. The combination index curves were calculated according to Chou-Talalay method. B) Combination indexes for SU-DHL-6/16 cell lines and primary MZL and DLBCL cells treated with different combinations of GS-1101 and LBH589 concentrations.