These include drug resistance genes (ABCC1 (MRP-1), BCL-2, TOP1, TOP2A, TOP2B, and TP53), drug metabolism genes (GSTpi, CYP1A1, BLMH and DHFR), DNA repair genes (MSH2, BRCA2, and XPC), cell cycle genes (CDK2, CDK4, and CDKN1A) and the transcription factor HIF1A. These data suggest that chemoresistance effects of targeted inhibition of Trx-1 in DLBCL cells are mediated, at least in part, by down-regulation of several key genes that are known to play a role in drug resistance mechanisms. This evidence concerns the gene TOP1 and diffuse large B-cell lymphoma.