Antigens in lymphoma development--current knowledge and future directions.

Lymphomas are a very heterogeneous group of tumors of mature lymphoid cells with quite different morphology, genetics and clinical characteristics, which is also reflected in the numerous entities and sub-entities defined in the most recent WHO classification. Today, it is well-established that lymphomas can evolve due to both 'cell-intrinsic' factors (e.g. acquired genomic aberrations) and 'cell-extrinsic' factors (e.g. microenvironmental stimuli), although for most lymphoma subtypes the precise implicated mechanisms remain to be elucidated. In this thematic issue, a series of reviews have been collected focusing on key evidence for (i) direct or indirect links between antigens and lymphoma development; and, (ii) activated signaling pathways that play an essential role in tumor evolution and progression. Finally, strategies for the management of lymphomas developing due to viral and bacterial infection as well as novel promising therapies designed to hit specific cellular pathways (e.g. B-cell receptor inhibitors) will be summarized and discussed. Altogether, this issue will give the reader important insights into the current knowledge of the diverse mechanisms that come into play during lymphoma development as well as clues to future directions within this broad and intense research field.