The combination of lenalidomide and BI-D1870 demonstrated a significant enhancement of cytotoxicity and downregulation of IRF4 and MYC. H929 (A-B) and JJN3 (C-D) were treated with the indicated doses of lenalidomide and BI-D1870 (μM) for various times, and was followed by MTT assay (A and C, day 5) and immunoblotting assay (B and D, at various time points).