Therefore, since ALCL cells express unusually high levels of high-affinity IL-2 receptors, these cells may be highly sensitive to IL-2 and thus may be able to react to sub-functional concentrations of IL-2 in the serum and/or produced by reactive T lymphocytes within the lymphoma tumor site, resulting in enhanced ALCL cell growth. This evidence concerns the gene IL2 and anaplastic large cell lymphoma.