It is plausible to expect that tumour-infiltrating CD8+ effector T cells may result immunosuppressed in DLBCL, as a consequence of aforementioned mechanisms of cytokine dysregulation (decreased TFH-derived cytotoxic IL-21 and increased autocrine IL-10) and PD-L1 upregulation, compromising efficient anti-lymphoma immune responses and facilitating immune escape (Figure 2, right). Here, IL21 is linked to lymphoma.