Given the pivotal role of the B-cell follicle in B-cell proliferation, and the fact that the follicle centre has the highest proliferation fraction of any structure in the body, it would be reasonable to expect that the potential for the development of aberrant (neoplastic) growth within it would be relatively high, especially when compared to other lymphoid compartments. However, in all current lymphoma classifications only one entity, namely follicular lymphoma, is acknowledged as having any relation to the follicle. As knowledge of the immunophenotype and function of the normal follicle has increased, it has become evident that many lymphomas, including some examples of Hodgkin's disease, are related to the B-cell follicle and as a consequence manifest a follicular growth pattern. This has implications for the pathogenesis of these tumours and may point the way to novel therapeutic options.