Only a small number of high-risk subsets of DLBCL are associated with increased expression of multidrug pumps (i.e., P-glycoprotein; MDR1/ABCB1) [189, 220, 221] and overexpression does not appear to be consistently associated with chemoresistance in DLBCL [221, 222]. Here, ABCB1 is linked to diffuse large B-cell lymphoma.