ABCB1 and diffuse large B-cell lymphoma: Due to the non-clarity of their clinical relevance in comparison to Bcl-2, we investigated if coexpression of the most common MDR proteins (P-gp/ABCB1, MRP1/ABCC1, and BCRP/ABCG2) and survivin is associated with R-CHOP treatment resistance in previously untreated patients with DLBCL.