ABCC1 and diffuse large B-cell lymphoma: Our results, similar to the study by Gündüz et al. [47] and Oshawa et al. [16], showed an overexpression of MRP1/ABCC1 and a high IRS at initial diagnosis, particularly in patients who would develop R/R DLBCL after first-line R-CHOP treatment, so that it may serve as a predictive indicator to the treatment response.