Abstract Background MicroRNAs (miRs) are involved in tumor progression by regulating tumor cells and tumor microenvironment. MiR21 is overexpressed in diffuse large B-cell lymphoma (DLBCL) and its biological impact on tumor microenvironment remains unclear. Methods MiR21 was assessed by quantitative RT-PCR in patients with newly diagnosed DLBCL. https://www.nacrack.com/