Recent studies provide evidence that Reed-Sternberg (R-S) cells produce factors that may explain the characteristic inflammatory infiltrate in the affected tissues of Hodgkin lymphoma. The various chemokines and cytokines that are produced lead to a preferential influx of Th2-type T cells and suppress Th1-type immune responses. Overall, the immunophenotype of the lymphocytes surrounding the R-S cells is consistent with anergic and/or Th2-type T cells. Therefore, these cells do not support a cytotoxic anti-tumor response. Since the R-S cells are neoplastic B cells, the cytokines produced by these T cells may in fact help their growth and/or survival. The production and induction of various other cytokines may also explain the influx of eosinophils (IL-5, eotaxin) and plasma cells (IL-6). Differences in chemokine and cytokine production may be responsible for the differences between the histological subtypes.